Makefile: rockchip: Support SPL-alone mkimage

Add SPL-alone mkimage tooling support via Makefile for
few platforms or boards used in rockchip family.

With this users would get rid of explicitly creating
mkimage tool for rockchip rksd or rkspi boot modes.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/Makefile b/Makefile
index 4eeba6f..be7292d 100644
--- a/Makefile
+++ b/Makefile
@@ -911,7 +911,7 @@
 ALL-y += u-boot-with-dtb.bin
 endif
 
-ifeq ($(CONFIG_ARCH_ROCKCHIP)$(CONFIG_SPL)$(CONFIG_TPL),yyy)
+ifeq ($(CONFIG_ARCH_ROCKCHIP)$(CONFIG_SPL),yy)
 ALL-y += idbloader.img
 endif
 
@@ -1386,11 +1386,19 @@
 ROCKCHIP_IMG_TYPE := rksd
 endif
 
+# TPL + SPL
+ifeq ($(CONFIG_SPL)$(CONFIG_TPL),yy)
 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-rockchip.bin spl/u-boot-spl.bin FORCE
 	$(call if_changed,cat)
+else
+MKIMAGEFLAGS_idbloader.img = -n $(CONFIG_SYS_SOC) -T $(ROCKCHIP_IMG_TYPE)
+idbloader.img: spl/u-boot-spl.bin FORCE
+	$(call if_changed,mkimage)
+endif
+
 endif
 
 ifeq ($(CONFIG_ARCH_LPC32XX)$(CONFIG_SPL),yy)