mmc: simplify SDHCI Kconfig dependencies

We have a number of front-end drivers for SDHCI_PLTFM, some of them
use 'select MMC_SDHCI_PLTFM', others use 'depends on'. This is
inconsistent and confusing, and in one case has also led to a
build error because of incomplete dependencies:

warning: (MMC_SDHCI_PXAV3 && MMC_SDHCI_PXAV2 && MMC_SDHCI_BCM_KONA) selects MMC_SDHCI_PLTFM which has unmet direct dependencies (MMC && MMC_SDHCI)
drivers/built-in.o: In function `sdhci_sirf_resume':
:(.text+0xaaacb4): undefined reference to `sdhci_resume_host'
drivers/built-in.o: In function `sdhci_sirf_suspend':
:(.text+0xaaacf8): undefined reference to `sdhci_suspend_host'
drivers/built-in.o: In function `sdhci_sirf_probe':
:(.text+0xaaaf44): undefined reference to `sdhci_add_host'
:(.text+0xaaaf50): undefined reference to `sdhci_remove_host'

This changes Kconfig to use 'depends on MMC_SDHCI_PLTFM' for all these
cases, to fix the build error and make the logic more logical.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/Kconfig

@@ -216,8 +216,7 @@ config MMC_SDHCI_SIRF
 config MMC_SDHCI_PXAV3
 	tristate "Marvell MMP2 SD Host Controller support (PXAV3)"
 	depends on CLKDEV_LOOKUP
-	select MMC_SDHCI
-	select MMC_SDHCI_PLTFM
+	depends on MMC_SDHCI_PLTFM
 	default CPU_MMP2
 	help
 	  This selects the Marvell(R) PXAV3 SD Host Controller.
@@ -229,8 +228,7 @@ config MMC_SDHCI_PXAV3
 config MMC_SDHCI_PXAV2
 	tristate "Marvell PXA9XX SD Host Controller support (PXAV2)"
 	depends on CLKDEV_LOOKUP
-	select MMC_SDHCI
-	select MMC_SDHCI_PLTFM
+	depends on MMC_SDHCI_PLTFM
 	default CPU_PXA910
 	help
 	  This selects the Marvell(R) PXAV2 SD Host Controller.
@@ -264,7 +262,7 @@ config MMC_SDHCI_S3C_DMA
 config MMC_SDHCI_BCM_KONA
 	tristate "SDHCI support on Broadcom KONA platform"
 	depends on ARCH_BCM_MOBILE
-	select MMC_SDHCI_PLTFM
+	depends on MMC_SDHCI_PLTFM
 	help
 	  This selects the Broadcom Kona Secure Digital Host Controller
 	  Interface(SDHCI) support.