Get rid of use of compatibility API

make 'make ARCH=aarch64 CROSS_COMPILE=aarch64-linux-gnu- PLAT=mt8173
ENABLE_PLAT_COMPAT=0' work.

Change-Id: I13f35d8aef23dfa0e65883fa0be43f1513c9fef5
Signed-off-by: Koan-Sin Tan <koansin.tan@gmail.com>
diff --git a/plat/mediatek/mt8173/aarch64/plat_helpers.S b/plat/mediatek/mt8173/aarch64/plat_helpers.S
index af3a407..3347f55 100644
--- a/plat/mediatek/mt8173/aarch64/plat_helpers.S
+++ b/plat/mediatek/mt8173/aarch64/plat_helpers.S
@@ -34,6 +34,7 @@
 	.globl	plat_secondary_cold_boot_setup
 	.globl	plat_report_exception
 	.globl	platform_is_primary_cpu
+	.globl  plat_my_core_pos
 	.globl	plat_crash_console_init
 	.globl	plat_crash_console_putc
 
@@ -59,6 +60,22 @@
 	ret
 endfunc platform_is_primary_cpu
 
+#if !ENABLE_PLAT_COMPAT
+	/* -----------------------------------------------------
+	 * unsigned int plat_my_core_pos(void);
+	 *
+	 * result: CorePos = CoreId + (ClusterId << 2)
+	 * -----------------------------------------------------
+	 */
+func plat_my_core_pos
+	mrs     x0, mpidr_el1
+	and     x1, x0, #MPIDR_CPU_MASK
+	and     x0, x0, #MPIDR_CLUSTER_MASK
+	add     x0, x1, x0, LSR #6
+	ret
+endfunc plat_my_core_pos
+#endif
+
 	/* ---------------------------------------------
 	 * int plat_crash_console_init(void)
 	 * Function to initialize the crash console