mmc: sdhci: Add LPAE (Large Physical Address Extension) support

This change involves configuring the ADMA2 in 64-bit mode
based on the controller capabilities and setting up the
64-bit descriptor table so that driver can handle physical
addresses greater than 32-bits when LPAE is enabled.

Change-Id: I070d81212c180cbf23a041ff218106add513c47d
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>