Remove fit-dtb.blob* in clean target.

Support for compressed fit-dtb.blob was added in:

  commit 95f4bbd581cf ("lib: fdt: Allow LZO and GZIP DT compression in
  U-Boot")

Adjust Makefile to also clean compressed blobs.

Signed-off-by: Vagrant Cascadian <vagrant@reproducible-builds.org>
diff --git a/Makefile b/Makefile
index fa47b06..d122476 100644
--- a/Makefile
+++ b/Makefile
@@ -1791,7 +1791,7 @@
 			$(filter-out include, $(shell ls -1 $d 2>/dev/null))))
 
 CLEAN_FILES += include/bmp_logo.h include/bmp_logo_data.h \
-	       boot* u-boot* MLO* SPL System.map fit-dtb.blob
+	       boot* u-boot* MLO* SPL System.map fit-dtb.blob*
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_DIRS  += include/config include/generated spl tpl \