mmc: jz4740: Drop dependency on MACH_JZ4740/80

Depending on MACH_JZ4740 | MACH_JZ4780 prevent us from creating a generic
kernel that works on more than one MIPS board. Instead, we just depend on
MIPS being set.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/Kconfig

@@ -773,7 +773,7 @@ config MMC_SH_MMCIF
 
 config MMC_JZ4740
 	tristate "Ingenic JZ47xx SD/Multimedia Card Interface support"
-	depends on MACH_JZ4740 || MACH_JZ4780
+	depends on MIPS
 	help
 	  This selects support for the SD/MMC controller on Ingenic
 	  JZ4740, JZ4750, JZ4770 and JZ4780 SoCs.