drm/amd: Fix spelling typo in comment

Signed-off-by: oushixiong <oushixiong@kylinos.cn>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/include/atomfirmware.h

@@ -3,7 +3,7 @@
 *  File Name      atomfirmware.h
 *  Project        This is an interface header file between atombios and OS GPU drivers for SoC15 products
 *
-*  Description    header file of general definitions for OS nd pre-OS video drivers 
+*  Description    header file of general definitions for OS and pre-OS video drivers
 *
 *  Copyright 2014 Advanced Micro Devices, Inc.
 *