mediatek: common: add support to boot BL33 in AArch64 mode

Add support to boot BL33 in AArch64 mode.
Make this function being empty when building for ARMv7.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

plat/mediatek/common/mtk_plat_common.c

@@ -101,8 +101,11 @@ void boot_to_kernel(uint64_t x1, uint64_t x2, uint64_t x3, uint64_t x4)
 
 uint32_t plat_get_spsr_for_bl33_entry(void)
 {
+	uint32_t spsr = 0;
+
+#if (ARM_ARCH_MAJOR > 7)
+#ifndef KERNEL_IS_DEFAULT_64BIT
 	unsigned int mode;
-	uint32_t spsr;
 	unsigned int ee;
 	unsigned long daif;
 
@@ -116,6 +119,13 @@ uint32_t plat_get_spsr_for_bl33_entry(void)
 	daif = DAIF_ABT_BIT | DAIF_IRQ_BIT | DAIF_FIQ_BIT;
 
 	spsr = SPSR_MODE32(mode, 0, ee, daif);
+#else
+	INFO("Secondary bootloader is AArch64\n");
+
+	spsr = SPSR_64(MODE_EL2, MODE_SP_ELX, DISABLE_ALL_EXCEPTIONS);
+#endif
+#endif
+
 	return spsr;
 }