Makefile: rockchip: Suffix platform type with tpl name

Most of the platforms uses the platform type on their boot
stage image naming conventions in makefile like,

u-boot-x86-start16-tpl.bin - x86 start16 TPL bin
u-boot-spl-mtk.bin - Mediatek SPL bin

This would help to understand the users to what that
particular image belongs to? and less confused.

On that note, suffix platform type rockchip for existing
u-boot-tpl.img so now it become u-boot-tpl-rockchip.bin

Also, bin is more conventional way to include it on tools
like binman, pad_cat etc in future patches.

Note: usage of platform type doesn't follow consistent order
as of now.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/Makefile b/Makefile
index 7947f34..4eeba6f 100644
--- a/Makefile
+++ b/Makefile
@@ -1386,10 +1386,10 @@
 ROCKCHIP_IMG_TYPE := rksd
 endif
 
-MKIMAGEFLAGS_u-boot-tpl.img = -n $(CONFIG_SYS_SOC) -T $(ROCKCHIP_IMG_TYPE)
-tpl/u-boot-tpl.img: tpl/u-boot-tpl.bin FORCE
+MKIMAGEFLAGS_u-boot-tpl-rockchip.bin = -n $(CONFIG_SYS_SOC) -T $(ROCKCHIP_IMG_TYPE)
+tpl/u-boot-tpl-rockchip.bin: tpl/u-boot-tpl.bin FORCE
 	$(call if_changed,mkimage)
-idbloader.img: tpl/u-boot-tpl.img spl/u-boot-spl.bin FORCE
+idbloader.img: tpl/u-boot-tpl-rockchip.bin spl/u-boot-spl.bin FORCE
 	$(call if_changed,cat)
 endif