mfd: Use NULL to initialise NULL pointers in ab8500-debugfs

Partly for coding style reasons, but mostly because sparse warns on it.

Signed-off-by: Mark Brown <[e-mail]>
Acked-by: Mattias Wallin <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/mfd/ab8500-debugfs.c

···
 	},
 	[AB8500_DBI] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[AB8500_ECI_AV_ACC] = {
 		.num_ranges = 1,
···
 	},
 	[0x9] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[AB8500_GPADC] = {
 		.num_ranges = 1,
···
 	},
 	[AB8500_INTERRUPT] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[AB8500_RTC] = {
 		.num_ranges = 1,
···
 	},
 	[0x11] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[0x12] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[0x13] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[0x14] = {
 		.num_ranges = 0,
-		.range = 0,
+		.range = NULL,
 	},
 	[AB8500_OTP_EMUL] = {
 		.num_ranges = 1,