QcomModulePkg: System-As-Root on non-A/B for VB1 targets

According to System-As-Root behaviour, system.img should contain both
system content and ramdisk content, and should be mounted at
root(‘/’). As of today A/B already has system-as-root by default.
Now, we need to add support for the same even on non-A/B.

This change only valid for VB1 targets.

Change-Id: Ic1184aadd9dae975ecf09ab8ea2c08310fc29fb9
diff --git a/AndroidBoot.mk b/AndroidBoot.mk
index 2b7416f..51c1d6e 100644
--- a/AndroidBoot.mk
+++ b/AndroidBoot.mk
@@ -28,6 +28,12 @@
 	VERIFIED_BOOT := VERIFIED_BOOT=0
 endif
 
+ifeq ($(BOARD_BUILD_SYSTEM_ROOT_IMAGE),true)
+        BUILD_SYSTEM_ROOT_IMAGE := BUILD_SYSTEM_ROOT_IMAGE=1
+else
+        BUILD_SYSTEM_ROOT_IMAGE := BUILD_SYSTEM_ROOT_IMAGE=0
+endif
+
 ifeq ($(BOARD_AVB_ENABLE),true)
 	VERIFIED_BOOT_2 := VERIFIED_BOOT_2=1
 else
@@ -80,6 +86,7 @@
 	$(MAKE) -C bootable/bootloader/edk2 \
 		BOOTLOADER_OUT=../../../$(ABL_OUT) \
 		all \
+		$(BUILD_SYSTEM_ROOT_IMAGE) \
 		$(VERIFIED_BOOT) \
 		$(VERIFIED_BOOT_2) \
 		$(VERIFIED_BOOT_LE) \