drm/amd/dc: fix semicolon.cocci warnings

drivers/gpu/drm/amd/amdgpu/../display/dc/gpio/gpio_service.c:134:2-3: Unneeded semicolon

 Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

Fixes: 80be23c57868 ("drm/amd/dc: Add dc display driver (v2)")
CC: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>