sh: export clear_user_page() for the modules that need it.

Some modules seem to need this, so we export it..
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/sh_ksyms.c

@@ -100,6 +100,7 @@ EXPORT_SYMBOL(flush_cache_all);
 EXPORT_SYMBOL(flush_cache_range);
 EXPORT_SYMBOL(flush_dcache_page);
 EXPORT_SYMBOL(__flush_purge_region);
+EXPORT_SYMBOL(clear_user_page);
 #endif
 
 #if defined(CONFIG_SH7705_CACHE_32KB)