Revert "rockchip: add subtarget rk356x init support"

This reverts commit bbfc031.
This part is identical to armv8 generic, remove redundant code.

Author: aiamadeus

include/target.mk

@@ -234,7 +234,6 @@ ifeq ($(DUMP),1)
     CPU_TYPE ?= generic
     CPU_CFLAGS_generic = -mcpu=generic
     CPU_CFLAGS_cortex-a53 = -mcpu=cortex-a53
-    CPU_CFLAGS_cortex-a55 = -mcpu=cortex-a55
   endif
   ifeq ($(ARCH),arc)
     CPU_TYPE ?= arc700

target/linux/rockchip/Makefile

@@ -5,7 +5,7 @@ include $(TOPDIR)/rules.mk
 BOARD:=rockchip
 BOARDNAME:=Rockchip
 FEATURES:=ext4 audio usb usbgadget display gpio fpu pci pcie rootfs-part boot-part squashfs
-SUBTARGETS:=armv8 rk356x
+SUBTARGETS:=armv8
 
 KERNEL_PATCHVER=5.15
 KERNEL_TESTING_PATCHVER=5.10

target/linux/rockchip/armv8/target.mk

@@ -3,6 +3,6 @@ SUBTARGET:=armv8
 BOARDNAME:=RK33xx boards (64 bit)
 
 define Target/Description
-	Build firmware image for Rockchip RK356x devices.
+	Build firmware image for Rockchip RK33xx devices.
 	This firmware features a 64 bit kernel.
 endef