Makefile: also remove .gcno files when cleaning

Left over .gcno files from old builds can really confuse gcov and the
user expects a clean slate after "make clean". Make clean mean clean.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220204204335.1689602-4-alex.bennee@linaro.org>
diff --git a/Makefile b/Makefile
index db9a788..e5fd1ebd 100644
--- a/Makefile
+++ b/Makefile
@@ -206,7 +206,8 @@
 clean: recurse-clean
 	-$(quiet-@)test -f build.ninja && $(NINJA) $(NINJAFLAGS) -t clean || :
 	-$(quiet-@)test -f build.ninja && $(NINJA) $(NINJAFLAGS) clean-ctlist || :
-	find . \( -name '*.so' -o -name '*.dll' -o -name '*.[oda]' \) -type f \
+	find . \( -name '*.so' -o -name '*.dll' -o \
+		  -name '*.[oda]' -o -name '*.gcno' \) -type f \
 		! -path ./roms/edk2/ArmPkg/Library/GccLto/liblto-aarch64.a \
 		! -path ./roms/edk2/ArmPkg/Library/GccLto/liblto-arm.a \
 		-exec rm {} +