mmc: card: Add BKOPS unit tests

The BKOPS tests check the following scenarios:
- Starting BKOPS delayed work, level 1
- Starting BKOPS delayed work, level 1, with HPI
- Cancel starting BKOPS delayed work, when a request is received
- Starting BKOPS urgent, level 2,3
- Starting BKOPS urgent with 2 requests

Change-Id: I3ec8a8bee363cbb8a78c8c2f2d006dec12dbd005
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>