soc: qcom: rpmh_master_stat: skip apss stats if rpmh_unit_base available

APSS master stats can be read in two ways with APSS SMEM ID and rpmh
unit_base.

This change adds support to skip reading apss master stats from SMEM
when rpmh_unit_base present.

Change-Id: I13ba0474dac8c8d0f506ffab1008e696b583fc20
Signed-off-by: Tushar Nimkar <tnimkar@codeaurora.org>