in nexus 4 8921_l6 regulates earjack_debug but in E970 it regulates msm_sdcc.3 (external sdcard)

Change-Id: Ic72be1ab150697a78c55e68435a3cb23f0ce1ce9
add MSM_SDC3 (external sdcard) support
use CONFIG_MMC_MSM_SDC3_SUPPORT to choose between sdc3 and earjack debug
drivers for PN544 NFC
add PN544 NFC support
Enable external SDCard