remoteproc: qcom: q6v5-mss: Improve readability of reset_assert

Define AXI_GATING_VALID_OVERRIDE and fixup comments to improve readability
of Q6 modem reset sequence on SC7180 SoCs.

Reviewed-by: Evan Green <evgreen@chromium.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Link: https://lore.kernel.org/r/20200123131236.1078-3-sibis@codeaurora.org


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>