functions: write permission in config.{guess,sub}

avr-libc doesn't have write permissions in these by default in the 1.8.1
tar release, this caused an error during build with
CT_OVERIDE_CONFIG_GUESS_SUB enabled.

chmod u+w them before overriding to avoid an this error.

Signed-off-by: Erico Nunes <nunes.erico@gmail.com>

scripts/functions

@@ -1132,7 +1132,9 @@ CT_Patch() {
             eval ${cfg}="${CT_LIB_DIR}/scripts/${cfg/_/.}"
             [ -e "${CT_TOP_DIR}/scripts/${cfg/_/.}" ] && eval ${cfg}="${CT_TOP_DIR}/scripts/${cfg/_/.}"
             # Can't use CT_DoExecLog because of the '{} \;' to be passed un-mangled to find
-            find . -type f -name "${cfg/_/.}" -exec cp -v "${!cfg}" {} \; |CT_DoLog ALL
+            find . -type f -name "${cfg/_/.}" \
+                -exec chmod -v u+w {} \; \
+                -exec cp -v "${!cfg}" {} \; |CT_DoLog ALL
         done
     fi