drm/amdgpu/mes12: optimize MES pipe FW version fetching

drm/amdgpu/mes12: optimize MES pipe FW version fetching

commit 34779e14461cf715238dec5fd43a1e11977ec115 upstream.

Don't fetch it again if we already have it.  It seems the
registers don't reliably have the value at resume in some
cases.

Fixes: 785f0f9fe742 ("drm/amdgpu: Add mes v12_0 ip block support (v4)")
Reviewed-by: Shaoyun.liu <Shaoyun.liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 9e7b08d239c2f21e8f417854f81e5ff40edbebff)
Cc: stable@vger.kernel.org # 6.12.x
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>