soc/mediatek/mt8195: add apusys init flow

Set up APU mbox's functional configuration registers.

BUG=b:203145462
BRANCH=cherry
TEST=boot cherry correctly

Signed-off-by: Flora Fu <flora.fu@mediatek.com>
Change-Id: I5053d5e1f1c2286c9dce280ff83e8b8611b573b9
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58794
Reviewed-by: Yu-Ping Wu <yupingso@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/mediatek/mt8195/soc.c b/src/soc/mediatek/mt8195/soc.c
index 20bd226..80ca3d9 100644
--- a/src/soc/mediatek/mt8195/soc.c
+++ b/src/soc/mediatek/mt8195/soc.c
@@ -2,6 +2,7 @@
 
 #include <bootmem.h>
 #include <device/device.h>
+#include <soc/apusys.h>
 #include <soc/devapc.h>
 #include <soc/dfd.h>
 #include <soc/emi.h>
@@ -28,6 +29,7 @@
 {
 	mtk_mmu_disable_l2c_sram();
 	dapc_init();
+	apusys_init();
 	mcupm_init();
 	sspm_init();