msm: cpr: Replace mutex with spinlock in atomic context

The CPR suspend is called in an atomic context which leads
to failure if mutex is used before disabling CPR. Replace
with spinlock to fix it.

Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>
(cherry picked from commit ea80e643a02dd1f7f3e8941f9ffdb430c5ca8c0e)

Change-Id: I2cabf0d831186e66417abc6869654e6f00425bdc
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>