soc: qcom: rpmh-rsc: tcs_is_free() can just check tcs_in_use

tcs_is_free() had two checks in it: does the software think that the
TCS is free and does the hardware think that the TCS is free.  I
couldn't figure out in which case the hardware could think that a TCS
was in-use but software thought it was free.  Apparently there is no
case and the extra check can be removed.  This apparently has already
been done in a downstream patch.

Suggested-by: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Maulik Shah <mkshah@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Maulik Shah <mkshah@codeaurora.org>
Link: https://lore.kernel.org/r/20200413100321.v4.7.Icf2213131ea652087f100129359052c83601f8b0@changeid


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