soc: qcom: smp2p: Add support for smp2p v2

soc: qcom: smp2p: Add support for smp2p v2

smp2p v2 adds support for allowing remote processors to write outbound
smp2p items without completing the feature negotiation. This is required
for processors that start before linux to write out signals like error
and clock ready and unblock their bootup.

If a remote processor only supports v1, smp2p can version down by
mirroring the peer version during the negotiation stage.

When using smp2p version 2, the remote does not wait for the ssr ack
before setting the items. To accommodate this, set the last_value of all
the entries to 0 when SSR is detected. This forces smp2p to detect the
new values written by the remote. Because the SSR ack is skipped, the
down transition of bits is missed in smp2p version 2.

Signed-off-by: Chris Lew <chris.lew@oss.qualcomm.com>
Signed-off-by: Deepak Kumar Singh <deepak.singh@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260127-smp2pv2-v3-2-4060b859b1e2@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>