Recovery: mount non-vfat external sd cards

Set fs type to auto for external sd cards to allow for non-vfat
formatted sd card, ie ext4

Change-Id: I92588e29b5eefd590db7b7c68e303488069a660d
Merge branch 'cm-10.1' of github.com:CyanogenMod/android_device_samsung_d2-common into cm-10.1