drm/xe: fix mcr semaphore locking for MTL

in commit 81593af6 ("drm/xe: Convert xe_mmio_wait32 to us so we can
stop using wait_for_us.") the mcr semaphore register read was
accidentally switched from waiting for the register to go to 1 to
waiting for the register to go to 0, so we need to flip it back.

Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>