mmc: Add hardware dependencies for sdhci-pxav3 and sdhci-pxav2

I seem to understand that the sdhci-pxav3 and sdhci-pxav2 drivers are
only needed on the MMP architecture. So add a hardware dependency on
ARCH_MMP, so that other users don't get to build useless drivers.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Chris Ball <chris@printf.net>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/Kconfig

@@ -230,6 +230,7 @@ config MMC_SDHCI_PXAV3
 	tristate "Marvell MMP2 SD Host Controller support (PXAV3)"
 	depends on CLKDEV_LOOKUP
 	depends on MMC_SDHCI_PLTFM
+	depends on ARCH_MMP || COMPILE_TEST
 	default CPU_MMP2
 	help
 	  This selects the Marvell(R) PXAV3 SD Host Controller.
@@ -242,6 +243,7 @@ config MMC_SDHCI_PXAV2
 	tristate "Marvell PXA9XX SD Host Controller support (PXAV2)"
 	depends on CLKDEV_LOOKUP
 	depends on MMC_SDHCI_PLTFM
+	depends on ARCH_MMP || COMPILE_TEST
 	default CPU_PXA910
 	help
 	  This selects the Marvell(R) PXAV2 SD Host Controller.