[mpp_frame]: Add color format print

1. Add color format print for all supported format.
2. Add RGB color fill function.

Change-Id: I79fb3f40402b6fb6e36883c99945e709723aee7d
Signed-off-by: Herman Chen <herman.chen@rock-chips.com>

inc/rk_mpi.h

@@ -196,6 +196,7 @@ MPP_RET mpp_destroy(MppCtx ctx);
 // coding type format function
 MPP_RET mpp_check_support_format(MppCtxType type, MppCodingType coding);
 void    mpp_show_support_format(void);
+void    mpp_show_color_format(void);
 
 #ifdef __cplusplus
 }