mmc: Add tracepoints of mmc block operations

Add tracepoints to record the start and end of each mmc block
operation.  This includes read, write, erase, secure erase,
trim, secure trim1 and secure trim 2, discard and
sanitize commands.

Change-Id: Ic5d1cbdb9adb940d8b1a2a13c73970023575df50
Signed-off-by: Ken Sumrall <ksumrall@android.com>