spi_qsd: shrink the probe function

Shrink the probe function to avoid the dependency of
the hardware interaction like clocks and bam. This avoids
the system boot up delay due to hardware depndency.

Change-Id: I4c92428eda4f4da653a05f3c8f0a8941aa621bec
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>