feat(mt8188): enable MTK_PUBEVENT_ENABLE

Enable MTK_PUBEVENT_ENABLE for subscribing CPUPM events. This
patch also corrects the header file naming.

Change-Id: Iabd89a4ead21ccafa833390367484bfea5d351f6
diff --git a/plat/mediatek/mt8188/plat_config.mk b/plat/mediatek/mt8188/plat_config.mk
index cff97cb..137318e 100644
--- a/plat/mediatek/mt8188/plat_config.mk
+++ b/plat/mediatek/mt8188/plat_config.mk
@@ -42,6 +42,7 @@
 CONFIG_MTK_SMP_EN := y
 CONFIG_MTK_CPU_SUSPEND_EN := y
 CPU_PM_TINYSYS_SUPPORT := y
+MTK_PUBEVENT_ENABLE := y
 
 MACH_MT8188 := 1
 $(eval $(call add_define,MACH_MT8188))