mmc: sdhci: revert MMC_PM_KEEP_POWER changes related to emmc

This change reverts the following gerrits as they cause the
timeout issues with Hynix cards. Also, the latest code supports
sleep/awake through CMD5 and hence MMC_PM_KEEP_POWER need not be
set for Hynix eMMC cards.

edcf5be "mmc: host: add detect vops chain"
09287cb "mmc: sdhci-msm: configure MMC_PM_KEEP_POWER for SDIO"
7cf603a "mmc: schci: add support for MMC_PM_KEEP_POWER in eMMC"
c085820 "mmc: core: set MMC_PM_KEEP_POWER for certain Hynix mmc cards"

CRs-Fixed: 947299
Change-Id: If863771191ee7c2b717d5817f4a88e4ad936653a
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>