mmc: complete unfinished move of CONFIG_MMC

Commit 7a777f6d6f35 ("mmc: Add generic Kconfig option") created
a Kconfig entry for this option without any actual moves, then
commit 44c798799f66 ("sunxi: Use Kconfig CONFIG_MMC") moved
instances only for SUNXI.

We generally do not like such partial moves.  This kind of work
is automated by tools/moveconfig.py, so it is pretty easy to
complete this move.

I am adding "default ARM || PPC || SANDBOX" (suggested by Tom).
This shortens the configs and will ease new board porting.

This commit was created as follows:

[1] Edit Kconfig (remove the "depends on", add the "default",
    copy the prompt and help message from Linux)

[2] Run 'tools/moveconfig.py -y -s -r HEAD MMC'

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 9983913..e9a1d18 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -1,10 +1,14 @@
 menu "MMC Host controller Support"
 
 config MMC
-	bool "Enable MMC support"
-	depends on ARCH_SUNXI || SANDBOX
+	bool "MMC/SD/SDIO card support"
+	default ARM || PPC || SANDBOX
 	help
-	  TODO: Move all architectures to use this option
+	  This selects MultiMediaCard, Secure Digital and Secure
+	  Digital I/O support.
+
+	  If you want MMC/SD/SDIO support, you should say Y here and
+	  also to your specific host controller driver.
 
 config DM_MMC
 	bool "Enable MMC controllers using Driver Model"