mmc: replace CONFIG_GENERIC_MMC with CONFIG_MMC

Now CONFIG_GENERIC_MMC and CONFIG_MMC match for all defconfig.
We do not need two options for the same feature.  Deprecate the
former.

This commit was generated with the sed script 's/GENERIC_MMC/MMC/'
and manual fixup of drivers/mmc/Kconfig.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/board/sunxi/board.c b/board/sunxi/board.c
index 01de42d..4404edb 100644
--- a/board/sunxi/board.c
+++ b/board/sunxi/board.c
@@ -284,7 +284,7 @@
 }
 #endif
 
-#ifdef CONFIG_GENERIC_MMC
+#ifdef CONFIG_MMC
 static void mmc_pinmux_setup(int sdc)
 {
 	unsigned int pin;