msm: ipa4: Mhi test case fix

Add offset for even_ring_bufs. Fix a buff offset error with
1pa3_write used in MHI test case. Remove support for
aggr_open tests for IPAv4.0 and greater.

CRs-fixed: 2158591
Change-Id: Ie207dc234787013163a1eecf11c8bde8bf7bcce4
Signed-off-by: Michael Adisumarta <madisuma@codeaurora.org>