Revert "Stop building boot-debug-*.img for GKI"

This reverts commit f1679a0c1dccaea1cd0f506f19522eae3ec2ba61.

Reason for revert: Unintentionally affects downstream, non-GSI-GKI products

Change-Id: Ic439ac586b9f27c7f83d0274f8ddfc6199cc05d5
diff --git a/target/board/generic_arm64/device.mk b/target/board/generic_arm64/device.mk
index 42474ef..fe56fd3 100644
--- a/target/board/generic_arm64/device.mk
+++ b/target/board/generic_arm64/device.mk
@@ -39,7 +39,4 @@
 PRODUCT_BUILD_VENDOR_BOOT_IMAGE := false
 PRODUCT_BUILD_RECOVERY_IMAGE := false
 
-# GKI devices should use vendor_boot-debug.img instead.
-PRODUCT_BUILD_DEBUG_BOOT_IMAGE := false
-
 $(call inherit-product, $(SRC_TARGET_DIR)/product/generic_ramdisk.mk)
diff --git a/target/board/generic_x86_64/device.mk b/target/board/generic_x86_64/device.mk
index c82e90a..d28ace7 100755
--- a/target/board/generic_x86_64/device.mk
+++ b/target/board/generic_x86_64/device.mk
@@ -28,7 +28,4 @@
 PRODUCT_BUILD_VENDOR_BOOT_IMAGE := false
 PRODUCT_BUILD_RECOVERY_IMAGE := false
 
-# GKI devices should use vendor_boot-debug.img instead.
-PRODUCT_BUILD_DEBUG_BOOT_IMAGE := false
-
 $(call inherit-product, $(SRC_TARGET_DIR)/product/generic_ramdisk.mk)