drm/amdgpu: use drm_debug_enabled() to check for debug categories

Allow better abstraction of the drm_debug global variable in the
future. No functional changes.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: David (ChunMing) Zhou <David1.Zhou@amd.com>
Cc: amd-gfx@lists.freedesktop.org
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Sean Paul <sean@poorly.run>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/e30ddbd627be1fe1c67dd007e0d36f81a094bc91.1572258936.git.jani.nikula@intel.com

drivers/gpu/drm/amd/amdgpu/smu_v11_0_i2c.c

@@ -234,7 +234,7 @@ static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
 	DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
 		 (uint16_t)address, numbytes);
 
-	if (drm_debug & DRM_UT_DRIVER) {
+	if (drm_debug_enabled(DRM_UT_DRIVER)) {
 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
 			       16, 1, data, numbytes, false);
 	}
@@ -388,7 +388,7 @@ static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
 	DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
 		  (uint16_t)address, bytes_received);
 
-	if (drm_debug & DRM_UT_DRIVER) {
+	if (drm_debug_enabled(DRM_UT_DRIVER)) {
 		print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
 			       16, 1, data, bytes_received, false);
 	}