rtc: remove unneeded 'fast_io' parameter in regmap_config

When using MMIO with regmap, fast_io is implied. No need to set it
again.

Signed-off-by: Wolfram Sang <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Alexandre Belloni <[e-mail]>

drivers/rtc/rtc-meson.c

···
 	.val_bits	= 32,
 	.reg_stride	= 4,
 	.max_register	= RTC_REG4,
-	.fast_io	= true,
 };
 
 /* RTC front-end serialiser controls */