ARMv7: u8500_href: Add missing header to fix compiler warning

Fix the compiler warning

u8500_href.c: In function 'hrefplus_mmc_power_init':
u8500_href.c:258: warning: implicit declaration of function 'prcmu_i2c_read'
u8500_href.c:265: warning: implicit declaration of function 'prcmu_i2c_write'

by adding the missing header file.
Signed-off-by: NDirk Behme <dirk.behme@googlemail.com>

board/st-ericsson/u8500/u8500_href.c

@@ -27,6 +27,7 @@
 #include <asm/arch/hardware.h>
 #include <asm/arch/sys_proto.h>
 #ifdef CONFIG_MMC
+#include "prcmu-fw.h"
 #include "../../../drivers/mmc/arm_pl180_mmci.h"
 #endif