Makefile: add drivers/video/u_boot_logo.S to clean

make sandbox_defconfig
make mrproper
make tests

fails with

../drivers/video/u_boot_logo.S: Assembler messages:
../drivers/video/u_boot_logo.S:5: Error: file not found: drivers/video/u_boot_logo.bmp

We have to delete the generated file.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

Makefile

@@ -2186,7 +2186,8 @@ CLEAN_DIRS  += $(MODVERDIR) \
 	       $(foreach d, spl tpl, $(patsubst %,$d/%, \
 			$(filter-out include, $(shell ls -1 $d 2>/dev/null))))
 
-CLEAN_FILES += include/bmp_logo.h include/bmp_logo_data.h tools/version.h \
+CLEAN_FILES += include/bmp_logo.h include/bmp_logo_data.h \
+	       drivers/video/u_boot_logo.S tools/version.h \
 	       u-boot* MLO* SPL System.map fit-dtb.blob* \
 	       u-boot-ivt.img.log u-boot-dtb.imx.log SPL.log u-boot.imx.log \
 	       lpc32xx-* bl31.c bl31.elf bl31_*.bin image.map tispl.bin* \