lpc32xx: add lpc32xx-spl.bin boot image target

Signed-off-by: Albert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>
diff --git a/include/image.h b/include/image.h
index 0e6af00..3844be6 100644
--- a/include/image.h
+++ b/include/image.h
@@ -242,6 +242,7 @@
 #define IH_TYPE_ATMELIMAGE	18	/* ATMEL ROM bootable Image	*/
 #define IH_TYPE_SOCFPGAIMAGE	19	/* Altera SOCFPGA Preloader	*/
 #define IH_TYPE_X86_SETUP	20	/* x86 setup.bin Image		*/
+#define IH_TYPE_LPC32XXIMAGE	21	/* x86 setup.bin Image		*/
 
 /*
  * Compression Types