kbuild: Delete .builtin-dtbs.S when running make clean

The makefile tries to delete a file named ".builtin-dtb.S" but the file
created by scripts/Makefile.vmlinux is actually called ".builtin-dtbs.S".

Fixes: 654102d ("kbuild: add generic support for built-in boot DTBs")
Cc: [email protected]
Signed-off-by: Charles Mirabile <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>
Link: https://patch.msgid.link/[email protected]
[nathan: Small commit message adjustments]
Signed-off-by: Nathan Chancellor <[email protected]>

Author: Charles Mirabile

Makefile

@@ -1650,7 +1650,7 @@ CLEAN_FILES += vmlinux.symvers modules-only.symvers \
 	       modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
 	       compile_commands.json rust/test \
 	       rust-project.json .vmlinux.objs .vmlinux.export.c \
-               .builtin-dtbs-list .builtin-dtb.S
+               .builtin-dtbs-list .builtin-dtbs.S
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \