MAINTAINERS: remove atmel-mci-regs.h file

Remove atmel-mci-regs.h file since it has been merged in atmel-mci.c.
Signed-off-by: NLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

MAINTAINERS

@@ -1896,7 +1896,6 @@ ATMEL AT91 / AT32 MCI DRIVER
 M:	Ludovic Desroches <ludovic.desroches@atmel.com>
 S:	Maintained
 F:	drivers/mmc/host/atmel-mci.c
-F:	drivers/mmc/host/atmel-mci-regs.h
 
 ATMEL AT91 / AT32 SERIAL DRIVER
 M:	Nicolas Ferre <nicolas.ferre@atmel.com>