mtd: move NAND files into a raw/ subdirectory

NAND flavors, like serial and parallel, have a lot in common and would
benefit to share code. Let's move raw (parallel) NAND specific code in a
raw/ subdirectory, to ease the addition of a core file in nand/ and the
introduction of a spi/ subdirectory specific to SPI NANDs.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/doc/README.zynq b/doc/README.zynq
index 5b0672c..da977b2 100644
--- a/doc/README.zynq
+++ b/doc/README.zynq
@@ -63,7 +63,7 @@
   spi - drivers/spi/zynq_spi.c
   qspi - drivers/spi/zynq_qspi.c
   i2c - drivers/i2c/zynq_i2c.c
-  nand - drivers/mtd/nand/zynq_nand.c
+  nand - drivers/mtd/nand/raw/zynq_nand.c
 - Done proper cleanups on board configurations
 - Added basic FDT support for zynq boards
 - d-cache support for zynq_gem.c