image.mk: add support for specifying a different suffix for the initramfs kernel

Signed-off-by: Felix Fietkau <[email protected]>

include/image.mk

@@ -309,9 +309,10 @@ define Device/Init
   IMAGE_NAME = $$(IMAGE_PREFIX)-$$(1)-$$(2)
   KERNEL_PREFIX = $(1)
   KERNEL_SUFFIX := -kernel.bin
+  KERNEL_INITRAMFS_SUFFIX = $$(KERNEL_SUFFIX)
   KERNEL_IMAGE = $$(KERNEL_PREFIX)$$(KERNEL_SUFFIX)
   KERNEL_INITRAMFS_PREFIX = $$(IMAGE_PREFIX)-initramfs
-  KERNEL_INITRAMFS_IMAGE = $$(KERNEL_INITRAMFS_PREFIX)$$(KERNEL_SUFFIX)
+  KERNEL_INITRAMFS_IMAGE = $$(KERNEL_INITRAMFS_PREFIX)$$(KERNEL_INITRAMFS_SUFFIX)
   KERNEL_INITRAMFS_NAME = $$(KERNEL_NAME)-initramfs
   KERNEL_INSTALL :=
   KERNEL_NAME := vmlinux