mmc: sdhci-msm: Add SDCC debug feature

With latest release of HPG for SDCC, some debug features
were added to get useful information at hardware level at
time of any issue.

This change adds a provision to enter/exit SDCC debug mode.
And it dumps below debug info when SDHC encounters any issue:
- fsm history of sdhc
- newly added ADMA descriptor info.
- sdcc iib history.

And exits from auto-recovery disable upon dumping sdcc registers
so that FSM would move back to idle state. And enable testbus bit
to disable internal clk gating as per sdcc HPG to support debug
feature.

Change-Id: Ie490fa5cd255ee6ba8dbaa6d08075dfa17f25093
Signed-off-by: Ram Prakash Gupta <rampraka@codeaurora.org>