x86_64: remove unused patch

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 44884

target/linux/x86_64/patches/012-export_erase_write.patch

@@ -1,23 +0,0 @@
---- a/drivers/mtd/mtdblock.c
-+++ b/drivers/mtd/mtdblock.c
-@@ -63,7 +63,7 @@ static void erase_callback(struct erase_
- 	wake_up(wait_q);
- }
- 
--static int erase_write (struct mtd_info *mtd, unsigned long pos,
-+int erase_write (struct mtd_info *mtd, unsigned long pos,
- 			int len, const char *buf)
- {
- 	struct erase_info erase;
---- a/include/linux/mtd/mtd.h
-+++ b/include/linux/mtd/mtd.h
-@@ -414,6 +414,9 @@ extern void register_mtd_user (struct mt
- extern int unregister_mtd_user (struct mtd_notifier *old);
- void *mtd_kmalloc_up_to(const struct mtd_info *mtd, size_t *size);
- 
-+int erase_write (struct mtd_info *mtd, unsigned long pos,
-+		 int len, const char *buf);
-+
- void mtd_erase_callback(struct erase_info *instr);
- 
- static inline int mtd_is_bitflip(int err) {