package/gcc: fix ARC failure to build in 2 phases.

When working with GCC initial at override source dir mode the
HOST_GCC_INITIAL_POST_PATCH_HOOKS is not called and compilation failes.
The solution is to use HOST_GCC_INITIAL_POST_RSYNC_HOOKS since this hook
is being called at override source dir mode.

Signed-off-by: Tal Zilcer <talz@ezchip.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/gcc/gcc-initial/gcc-initial.mk

@@ -34,6 +34,7 @@ define HOST_GCC_INITIAL_DISABLE_LIBGMON
 		$(@D)/libgcc/config.host
 endef
 HOST_GCC_INITIAL_POST_PATCH_HOOKS += HOST_GCC_INITIAL_DISABLE_LIBGMON
+HOST_GCC_INITIAL_POST_RSYNC_HOOKS += HOST_GCC_INITIAL_DISABLE_LIBGMON
 endif
 
 HOST_GCC_INITIAL_CONF_OPTS = \