drm/rockchip: Fix a typo

Fix a typo in comments.

Reported-by: Matthew Wilcox <[email protected]>
Signed-off-by: Andrew Kreimer <[email protected]>
Acked-by: Andy Yan<[email protected]>
Signed-off-by: Heiko Stuebner <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]

Author: algonell

drivers/gpu/drm/rockchip/cdn-dp-reg.h

@@ -77,7 +77,7 @@
 #define SOURCE_PIF_PKT_ALLOC_WR_EN	0x30830
 #define SOURCE_PIF_SW_RESET		0x30834
 
-/* bellow registers need access by mailbox */
+/* below registers need access by mailbox */
 /* source car addr */
 #define SOURCE_HDTX_CAR			0x0900
 #define SOURCE_DPTX_CAR			0x0904