[MTD] NAND modularize write function

Modularize the write function and reorganaize the internal buffer
management. Remove obsolete chip options and fixup all affected
users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/mtd/nand/toto.c

@@ -175,8 +175,6 @@ static int __init toto_init(void)
 
 	goto out;
 
- out_buf:
-	kfree(this->data_buf);
  out_mtd:
 	kfree(toto_mtd);
  out: