spi_qsd: Exit gracefully if the system is suspended

When the spi transfer is initiated during/after system suspend
the runtime pm framework returns an error. Before propagating the
error to the client driver call spi_finalize_current_message
to unblock the spi framework waiting for completion signal from
spi_qsd driver.

Change-Id: Ieee8b93200609143127dbac2f631a60bb028e046
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>