mhi: dev: satellite: save/restore interrupt context from rpmsg callback

Correct the spinlock API used in RPMSG interrupt context. If some
interrupt bits are disabled, they could end up being enabled
when lock is released. Avoid creating an erroneous state for
interrupts by using the API which does a save and restore of the
interrupt context.

CRs-Fixed: 2460637
Change-Id: I43a6cf62967aded3ed4341e56756987b5f96fc87
Acked-by: Bhaumik Vasav Bhatt <bbhatt@qti.qualcomm.com>
Signed-off-by: Sujeev Dias <sdias@codeaurora.org>