Added options for an internal SD card to be handled by recovery.

Exable uses in BoardConfig.mk:
	BOARD_HAS_SDCARD_INTERNAL := true
	BOARD_SDCARD_DEVICE_INTERNAL := /dev/block/mmcblk3p1

Setting BOARD_SDCARD_DEVICE_SECONDARY to the same value as
	BOARD_SDCARD_DEVICE_INTERNAL will allow the device to
	"fall back" to the internal SD card for other actions.

Change-Id: I2cf8ab4b1d385ac714f5b7416b915d059033d94b
diff --git a/etc/init.rc b/etc/init.rc
index d9e86d7..56c6542 100644
--- a/etc/init.rc
+++ b/etc/init.rc
@@ -8,6 +8,7 @@
     symlink /system/etc /etc
 
     mkdir /sdcard
+    mkdir /emmc
     mkdir /system
     mkdir /data
     mkdir /cache