drm/amdgpu: Replace one-elements array with flex-array members

One-element arrays are deprecated, and we are replacing them with
flexible array members instead. So, replace one-element array with
flexible-array member in structs ATOM_I2C_VOLTAGE_OBJECT_V3,
ATOM_ASIC_INTERNAL_SS_INFO_V2, ATOM_ASIC_INTERNAL_SS_INFO_V3,
and refactor the rest of the code accordingly.

Important to mention is that doing a build before/after this patch
results in no functional binary output differences.

This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/238
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101836 [1]

Signed-off-by: Paulo Miguel Almeida <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/display/dc/bios/bios_parser.c

···
 	if (!DATA_TABLES(ASIC_InternalSS_Info))
 		return BP_RESULT_UNSUPPORTED;
 
-	ss_table_header_include = GET_IMAGE(ATOM_ASIC_INTERNAL_SS_INFO_V3,
-		DATA_TABLES(ASIC_InternalSS_Info));
+	ss_table_header_include = ((ATOM_ASIC_INTERNAL_SS_INFO_V3 *) bios_get_image(&bp->base,
+				DATA_TABLES(ASIC_InternalSS_Info),
+				struct_size(ss_table_header_include, asSpreadSpectrum, 1)));
 	table_size =
 		(le16_to_cpu(ss_table_header_include->sHeader.usStructureSize)
 				- sizeof(ATOM_COMMON_TABLE_HEADER))
···
 	if (!DATA_TABLES(ASIC_InternalSS_Info))
 		return result;
 
-	header = GET_IMAGE(ATOM_ASIC_INTERNAL_SS_INFO_V2,
-		DATA_TABLES(ASIC_InternalSS_Info));
+	header = ((ATOM_ASIC_INTERNAL_SS_INFO_V2 *) bios_get_image(
+				&bp->base,
+				DATA_TABLES(ASIC_InternalSS_Info),
+				struct_size(header, asSpreadSpectrum, 1)));
 
 	memset(info, 0, sizeof(struct spread_spectrum_info));
 
···
 	if (!DATA_TABLES(ASIC_InternalSS_Info))
 		return 0;
 
-	header_include = GET_IMAGE(ATOM_ASIC_INTERNAL_SS_INFO_V2,
-			DATA_TABLES(ASIC_InternalSS_Info));
+	header_include = ((ATOM_ASIC_INTERNAL_SS_INFO_V2 *) bios_get_image(
+				&bp->base,
+				DATA_TABLES(ASIC_InternalSS_Info),
+				struct_size(header_include, asSpreadSpectrum, 1)));
 
 	size = (le16_to_cpu(header_include->sHeader.usStructureSize)
 			- sizeof(ATOM_COMMON_TABLE_HEADER))
···
 	if (!DATA_TABLES(ASIC_InternalSS_Info))
 		return number;
 
-	header_include = GET_IMAGE(ATOM_ASIC_INTERNAL_SS_INFO_V3,
-			DATA_TABLES(ASIC_InternalSS_Info));
+	header_include = ((ATOM_ASIC_INTERNAL_SS_INFO_V3 *) bios_get_image(&bp->base,
+				DATA_TABLES(ASIC_InternalSS_Info),
+				struct_size(header_include, asSpreadSpectrum, 1)));
 	size = (le16_to_cpu(header_include->sHeader.usStructureSize) -
 			sizeof(ATOM_COMMON_TABLE_HEADER)) /
 					sizeof(ATOM_ASIC_SS_ASSIGNMENT_V3);

drivers/gpu/drm/amd/include/atombios.h

···
    UCHAR  ucVoltageControlOffset;
    UCHAR  ucVoltageControlFlag;              // Bit0: 0 - One byte data; 1 - Two byte data
    UCHAR  ulReserved[3];
-   VOLTAGE_LUT_ENTRY asVolI2cLut[1];         // end with 0xff
+   VOLTAGE_LUT_ENTRY asVolI2cLut[];         // end with 0xff
 }ATOM_I2C_VOLTAGE_OBJECT_V3;
 
 // ATOM_I2C_VOLTAGE_OBJECT_V3.ucVoltageControlFlag
···
 typedef struct _ATOM_ASIC_INTERNAL_SS_INFO_V2
 {
   ATOM_COMMON_TABLE_HEADER         sHeader;
-  ATOM_ASIC_SS_ASSIGNMENT_V2        asSpreadSpectrum[1];      //this is point only.
+  ATOM_ASIC_SS_ASSIGNMENT_V2        asSpreadSpectrum[];      //this is point only.
 }ATOM_ASIC_INTERNAL_SS_INFO_V2;
 
 typedef struct _ATOM_ASIC_SS_ASSIGNMENT_V3
···
 typedef struct _ATOM_ASIC_INTERNAL_SS_INFO_V3
 {
   ATOM_COMMON_TABLE_HEADER         sHeader;
-  ATOM_ASIC_SS_ASSIGNMENT_V3        asSpreadSpectrum[1];      //this is pointer only.
+  ATOM_ASIC_SS_ASSIGNMENT_V3        asSpreadSpectrum[];      //this is pointer only.
 }ATOM_ASIC_INTERNAL_SS_INFO_V3;