efi_loader: set loaded image code/data type properly

These should be set according to the image type.  Shell.efi and SCT.efi
use these fields to determine what sort of image they are loading.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/pe.h

@@ -62,6 +62,12 @@ typedef struct _IMAGE_DATA_DIRECTORY {
 
 #define IMAGE_NUMBEROF_DIRECTORY_ENTRIES 16
 
+/* PE32+ Subsystem type for EFI images */
+#define IMAGE_SUBSYSTEM_EFI_APPLICATION         10
+#define IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER 11
+#define IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER      12
+#define IMAGE_SUBSYSTEM_SAL_RUNTIME_DRIVER      13
+
 typedef struct _IMAGE_OPTIONAL_HEADER64 {
 	uint16_t Magic; /* 0x20b */
 	uint8_t  MajorLinkerVersion;