Add phhgsi_a64_a for arm32 devices with 64bits binder

Change-Id: Ia6d61884740acc6319e857abd509c103d2b95abf
diff --git a/phhgsi_a64_a/BoardConfig.mk b/phhgsi_a64_a/BoardConfig.mk
new file mode 100644
index 0000000..221e881
--- /dev/null
+++ b/phhgsi_a64_a/BoardConfig.mk
@@ -0,0 +1,5 @@
+include build/make/target/board/generic_arm_a/BoardConfig.mk
+include device/phh/treble/board-base.mk
+
+BOARD_SYSTEMIMAGE_PARTITION_SIZE := 1572864000
+TARGET_USES_64_BIT_BINDER := true