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/build_helpers/options.mk b/plat/mediatek/build_helpers/options.mk
index 7b63a3e..0279648 100644
--- a/plat/mediatek/build_helpers/options.mk
+++ b/plat/mediatek/build_helpers/options.mk
@@ -12,6 +12,7 @@
 $(eval $(call add_defined_option,MTK_BL33_IS_64BIT))
 $(eval $(call add_defined_option,PLAT_XLAT_TABLES_DYNAMIC))
 $(eval $(call add_defined_option,MTK_ADAPTED))
+$(eval $(call add_defined_option,MTK_PUBEVENT_ENABLE))
 $(eval $(call add_defined_option,MTK_SOC))
 $(eval $(call add_defined_option,UART_CLOCK))
 $(eval $(call add_defined_option,UART_BAUDRATE))