msm: ipa: fix to match MHI Prime ring allocation size with dma api

This fix ensures to match the MHI Prime ring allocation sizes with
dma mapping/unmapping apis failing which may cause missed page table
mapping while invalidating the cache lines.

Change-Id: I6d2a70980a106036e046b135010a5c3d22c57fcb
Acked-by: Jyothi J <jyothij@qti.qualcom.com>
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>