mm/pgtable-generic.c: Export symbol __pte_offset_map

So JH7110 vdec can call pte_offset_map() when it is built as a module.

Signed-off-by: Hal Feng <hal.feng@starfivetech.com>

mm/pgtable-generic.c

@@ -302,6 +302,7 @@ nomap:
 	rcu_read_unlock();
 	return NULL;
 }
+EXPORT_SYMBOL(__pte_offset_map);
 
 pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
 			     unsigned long addr, spinlock_t **ptlp)