dmaengine: gpi: use spin_lock_irqsave instead of spin_lock_irq

depend on configuration events can be processed in irq context.
Use spin_lock_irqsave when acquiring spinlock so correct state
can be restored.

CRs-Fixed: 2149792
Change-Id: I14a22d589d33473874ab39bedc73d77457c454d1
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>