drm/amdgpu/mes11: optimize MES pipe FW version fetching

commit b71a2bb0 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: 028c3fb3 ("drm/amdgpu/mes11: initiate mes v11 support")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4083


Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>