Remove use of all deprecated APIs

Now it's possbile to build BL31 for MT8173 with ERROR_DEPRECATED=1.

Signed-off-by: Koan-Sin Tan <koansin.tan@gmail.com>
diff --git a/plat/mediatek/mt8173/drivers/spm/spm_mcdi.c b/plat/mediatek/mt8173/drivers/spm/spm_mcdi.c
index d715735..4d8422f 100644
--- a/plat/mediatek/mt8173/drivers/spm/spm_mcdi.c
+++ b/plat/mediatek/mt8173/drivers/spm/spm_mcdi.c
@@ -511,7 +511,10 @@
 
 void spm_mcdi_finish_for_on_state(unsigned long mpidr, unsigned int afflvl)
 {
-	unsigned long linear_id = platform_get_core_pos(mpidr);
+	unsigned long linear_id;
+
+	linear_id = ((mpidr & MPIDR_CLUSTER_MASK) >> 6) |
+			(mpidr & MPIDR_CPU_MASK);
 
 	spm_lock_get();
 	spm_mcdi_clear_cputop_pwrctrl_for_cluster_on(mpidr);