EMMC4.5: Enable eMMC 4.5 Large Sector Size feature

EMMC4.5: Enable eMMC 4.5 Large Sector Size feature

BZ: 29677

According to eMMC Spec 4.5, enable large sector size feature
(4KB Native sector) can improve performance for eMMC device
bigger than 256GB.

To enable this feature, it needs to disable the emulation mode of
eMMC device first. Since the emulation mode disable is one-time
operation, it should be done by vendor or FW.

This patch will not disable emulation mode. It will just check
whether the eMMC device emulation mode has been disabled. If true,
then the driver will report kernel block layer with 4KB hardware
sector while keep 512B size block on eMMC bus. This is just what
the eMMC 4.5 Spec requires.

Change-Id: If0306654b49e823bfffc4583f353bf696d07441f
Signed-off-by: Yunpeng Gao <yunpeng.gao@intel.com>
Reviewed-on: http://android.intel.com:8080/41776
Tested-by: Sun, Jianhua <jianhua.sun@intel.com>
Reviewed-by: Tang, Richard <richard.tang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>