cnss2: Increase mhi timeout to 30 sec for perf builds

cnss2: Increase mhi timeout in debug builds to 30sec from 10sec
for firmware download. Once MHI power On is done then the
timeout is reverted to default 10sec.

Change-Id: Ib18cda6da612d37e69cc6f1fee169f01d994daaa
Signed-off-by: Mohammed Siddiq <msiddiq@codeaurora.org>