Add generic AArch64 Cortex-A53 / GLES 2.0 target + HardKernel ODROID-C4 target (Amlogic S905x3)

Makefile

@@ -376,6 +376,53 @@ else ifeq ($(platform), sun8i_legacy)
 	
 #######################################
 
+# Generic AArch64 Cortex-A53 OpenGL ES 2.0 target
+else ifeq ($(platform), arm64_cortex_a53_gles2)
+	EXT ?= so
+	TARGET := $(TARGET_NAME)_libretro.$(EXT)
+	SHARED += -shared -Wl,--version-script=link.T
+	LDFLAGS +=  -Wl,--no-undefined
+	fpic = -fPIC
+	LIBS += -lrt
+	ARM_FLOAT_ABI_HARD = 0
+	FORCE_GLES = 1
+	SINGLE_PREC_FLAGS = 1
+	CPUFLAGS += -DHOST_CPU=0x20000006 -DTARGET_LINUX_ARMv8 -frename-registers
+	CFLAGS += -mcpu=cortex-a53 -mtune=cortex-a53 $(CPUFLAGS)
+	CXXFLAGS += -mcpu=cortex-a53 -mtune=cortex-a53 $(CPUFLAGS)
+	ASFLAGS += $(CFLAGS) -c -frename-registers -fno-strict-aliasing -ffast-math -ftree-vectorize
+	PLATFORM_EXT := unix
+	WITH_DYNAREC=arm64
+	HAVE_GENERIC_JIT = 0
+	HAVE_VULKAN = 0
+	HAVE_LTCG = 0
+	CORE_DEFINES += -DLOW_END
+
+#######################################
+
+# ARM64 SM1 Odroid C4
+else ifeq ($(platform), odroidc4)
+	EXT ?= so
+	TARGET := $(TARGET_NAME)_libretro.$(EXT)
+	SHARED += -shared -Wl,--version-script=link.T
+	LDFLAGS +=  -Wl,--no-undefined
+	fpic = -fPIC
+	LIBS += -lrt
+	ARM_FLOAT_ABI_HARD = 0
+	FORCE_GLES = 1
+	SINGLE_PREC_FLAGS = 1
+	CPUFLAGS += -DHOST_CPU=0x20000006 -DTARGET_LINUX_ARMv8 -frename-registers
+	CFLAGS += -mcpu=cortex-a55 -mtune=cortex-a55 $(CPUFLAGS)
+	CXXFLAGS += -mcpu=cortex-a55 -mtune=cortex-a55 $(CPUFLAGS)
+	ASFLAGS += $(CFLAGS) -c -frename-registers -fno-strict-aliasing -ffast-math -ftree-vectorize
+	PLATFORM_EXT := unix
+	WITH_DYNAREC=arm64
+	HAVE_GENERIC_JIT = 0
+	HAVE_VULKAN = 0
+	HAVE_LTCG = 0
+
+#######################################
+
 # ARM64 (switch-lakka)
 else ifeq ($(platform), arm64)
 	EXT ?= so