mmc: Issue new mmc reqs while dcmd is in progress

mmc: Issue new mmc reqs while dcmd is in progress

- Added support for issuing new mmc requests if
 queue barrier (QBR) feature is supported while
 direct CMD (DCMD) is in progress.
- Added kernel thread to process new mmc requests
 in mmc queue driver.

Bug 200138969
Bug 200193440

Change-Id: Id9b7cc55b98d756d174ba53e1d8e088df5f8c4d5
Reviewed-on: http://git-master/r/820227

Signed-off-by: R Raj Kumar <rrajk@nvidia.com>
Change-Id: I0aa4adc4ac5d22b4dab6291987bf7feb371e9249
Reviewed-on: http://git-master/r/1166880
GVS: Gerrit_Virtual_Submit
Reviewed-by: Venu Byravarasu <vbyravarasu@nvidia.com>