MIPS: Correct `nofpu' non-functionality

The `cpu_has_fpu' feature flag must not be hardcoded to 1 or the `nofpu'
kernel option will be ignored. Remove any such overrides and add a
cautionary note. Hardcoding to 0 is fine for FPU-less platforms.

Signed-off-by: Maciej W. Rozycki <[e-mail]>
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/9694/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/include/asm/cpu-features.h

···
 #ifndef cpu_has_octeon_cache
 #define cpu_has_octeon_cache	0
 #endif
+/* Don't override `cpu_has_fpu' to 1 or the "nofpu" option won't work.  */
 #ifndef cpu_has_fpu
 #define cpu_has_fpu		(current_cpu_data.options & MIPS_CPU_FPU)
 #define raw_cpu_has_fpu		(raw_current_cpu_data.options & MIPS_CPU_FPU)

arch/mips/include/asm/mach-cobalt/cpu-feature-overrides.h

···
 #define cpu_has_3k_cache	0
 #define cpu_has_4k_cache	1
 #define cpu_has_tx39_cache	0
-#define cpu_has_fpu		1
 #define cpu_has_32fpr		1
 #define cpu_has_counter		1
 #define cpu_has_watch		0

arch/mips/include/asm/mach-dec/cpu-feature-overrides.h

···
 /* Generic ones first.  */
 #define cpu_has_tlb			1
 #define cpu_has_tx39_cache		0
-#define cpu_has_fpu			1
 #define cpu_has_divec			0
 #define cpu_has_prefetch		0
 #define cpu_has_mcheck			0

arch/mips/include/asm/mach-ip22/cpu-feature-overrides.h

···
 #define cpu_has_tlb		1
 #define cpu_has_4kex		1
 #define cpu_has_4k_cache	1
-#define cpu_has_fpu		1
 #define cpu_has_32fpr		1
 #define cpu_has_counter		1
 #define cpu_has_mips16		0

arch/mips/include/asm/mach-ip32/cpu-feature-overrides.h

···
 /* Settings which are common for all ip32 CPUs */
 #define cpu_has_tlb		1
 #define cpu_has_4kex		1
-#define cpu_has_fpu		1
 #define cpu_has_32fpr		1
 #define cpu_has_counter		1
 #define cpu_has_mips16		0

arch/mips/include/asm/mach-loongson/cpu-feature-overrides.h

···
 #define cpu_has_dsp		0
 #define cpu_has_dsp2		0
 #define cpu_has_ejtag		0
-#define cpu_has_fpu		1
 #define cpu_has_ic_fills_f_dc	0
 #define cpu_has_inclusive_pcaches	1
 #define cpu_has_llsc		1

arch/mips/include/asm/mach-rm/cpu-feature-overrides.h

···
 #define cpu_has_tlb		1
 #define cpu_has_4kex		1
 #define cpu_has_4k_cache	1
-#define cpu_has_fpu		1
 #define cpu_has_32fpr		1
 #define cpu_has_counter		1
 #define cpu_has_watch		0