drm/msm/a2xx: stop over-complaining about the legacy firmware

drm/msm/a2xx: stop over-complaining about the legacy firmware

If the rootfs have a legacy A200 firmware, currently the driver will
complain each time the hw is reinited (which can happen a lot). E.g.
with GL testsuite the hw is reinited after each test, spamming the
console.

Make sure that the message is printed only once: when we detect the
firmware that doesn't support protection.

Fixes: 302295070d3c ("drm/msm/a2xx: support loading legacy (iMX) firmware")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/688098/
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>