linux: Introduce {vmlinux, vmlinuz}.efi kernel binary format

vmlinux.efi and vmlinuz.efi are standard file names for LoongArch
EFISTUB kernel.

Introduce them to build system.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Julien Olivain <ju.o@free.fr>

linux/Config.in

@@ -294,6 +294,10 @@ config BR2_LINUX_KERNEL_VMLINUX_BIN
 	bool "vmlinux.bin"
 	depends on BR2_mips || BR2_mipsel || BR2_sh
 
+config BR2_LINUX_KERNEL_VMLINUX_EFI
+	bool "vmlinux.efi"
+	depends on BR2_loongarch64
+
 config BR2_LINUX_KERNEL_VMLINUX
 	bool "vmlinux"
 
@@ -305,6 +309,10 @@ config BR2_LINUX_KERNEL_VMLINUZ_BIN
 	bool "vmlinuz.bin"
 	depends on BR2_mips || BR2_mipsel
 
+config BR2_LINUX_KERNEL_VMLINUZ_EFI
+	bool "vmlinuz.efi"
+	depends on BR2_loongarch64
+
 config BR2_LINUX_KERNEL_IMAGE_TARGET_CUSTOM
 	bool "custom target"
 	help

linux/linux.mk

@@ -262,12 +262,16 @@ else ifeq ($(BR2_LINUX_KERNEL_LINUX_BIN),y)
 LINUX_IMAGE_NAME = linux.bin
 else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_BIN),y)
 LINUX_IMAGE_NAME = vmlinux.bin
+else ifeq ($(BR2_LINUX_KERNEL_VMLINUX_EFI),y)
+LINUX_IMAGE_NAME = vmlinux.efi
 else ifeq ($(BR2_LINUX_KERNEL_VMLINUX),y)
 LINUX_IMAGE_NAME = vmlinux
 else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ),y)
 LINUX_IMAGE_NAME = vmlinuz
 else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ_BIN),y)
 LINUX_IMAGE_NAME = vmlinuz.bin
+else ifeq ($(BR2_LINUX_KERNEL_VMLINUZ_EFI),y)
+LINUX_IMAGE_NAME = vmlinuz.efi
 endif
 # The if-else blocks above are all the image types we know of, and all
 # come from a Kconfig choice, so we know we have LINUX_IMAGE_NAME set