msm: smp2p: optimize the smp2p spinlock test

smp2p spinlock test is running for higher loop count, so taking long time
to complete on Virtio setup.

Optimize the spinlock test by removing higher loop count and run the test
for configurable timeout with a default of 1 second.

Change-Id: I5673fa6d4eab9b16760fa7f4ec4439c359770699
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>