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: I0ece06feb8a5c0f4837126f44934d665c55294a2
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@codeaurora.org>
Signed-off-by: Shaik Sajida Bhanu <sbhanu@codeaurora.org>