BACKPORT: dsp-kernel: Add attribute and flag checks during map creation

A persistence map is expected to hold refs=2 during its creation.
However, the Fuzzy test can create a persistence map by configuring
a mismatch between attributes and flags using the KEEP MAP attribute
and FD NOMAP flags. This sets the map reference count to 1. The user
then calls fastrpc_internal_munmap_fd to free the map since it
doesn't check flags, which can cause a use-after-free (UAF) for the
file map and shared buffer. Add a check to restrict DMA handle
maps with invalid attributes.

Change-Id: I2f024ef99cc2a0487010504166e3af3433d5302d
Acked-by: Santosh <quic_ssakore@quicinc.com>
Signed-off-by: Abhinav Parihar <quic_parihar@quicinc.com>