spi: spi_qsd: Prevent deadlock while runtime pm is disabled

Do not call runtime suspend forcefully while holding the mutex as runtime
suspend also tries to acquire the same mutex. Instead acquire it properly
with the condition of runtime_pm enablement status without mutex.

Change-Id: I2347820e81ded0821e6f56a415af3bed17a951b4
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>