[klibc] kbuild: Fix permissions of headers

Small build fix carried in Debian, triggered by paranoid umask.

Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: maximilian attems <max@stro.at>

scripts/Kbuild.install

@@ -97,6 +97,7 @@ header:
 	$(Q)mkdir -p $(INSTALLROOT)$(INSTALLDIR)/$(KCROSS)bin
 	$(Q)$(MAKE) -C $(KLIBCKERNELSRC) ARCH=$(KLIBCARCH) INSTALL_HDR_PATH=$(INSTALLROOT)$(INSTALLDIR)/$(KCROSS) headers_install
 	$(Q)cp -rf usr/include/. $(INSTALLROOT)$(INSTALLDIR)/$(KCROSS)include/.
+	$(Q)chmod -R a+rX $(INSTALLROOT)$(INSTALLDIR)/$(KCROSS)include
 	$(Q)$(install-data) $(srctree)/klcc/klcc.1 $(INSTALLROOT)$(mandir)/man1/$(KCROSS)klcc.1
 	$(Q)$(install-bin) $(objtree)/klcc/$(KCROSS)klcc $(INSTALLROOT)$(bindir)