mmc: core: Add partial initialization support

This change adds the ability to partially initialize
the MMC card by using card Sleep/Awake sequence (CMD5).
Card will be sent to Sleep state during runtime/system suspend
and will be woken up during runtime/system resume.
By using this sequence the card doesn't need full initialization
which gives time reduction in system/runtime resume path.

Change-Id: I9a495a66a4ff2ce246de01a6ee1ae7d18d3f8b4d
Signed-off-by: Talel Shenhar <tatias@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Ram Prakash Gupta <rampraka@codeaurora.org>