mtd: onenand: Rename omap2 driver to avoid a build warning

As previously reported by Sudip Mukherjee for the Samsung driver, the
omap2 onenand driver is called omap2.c in our directory and omap2.c in
the tty/serial/ directory. If both drivers are compiled as modules, it
would produce the following warning:

warning: same module names found:
drivers/tty/serial/omap2.ko
drivers/mtd/nand/onenand/omap2.ko

Rename the onenand omap2 driver so that it fits the folder's
convention: onenand_omap2.c.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

mtd: onenand: Use a better name for samsung driver

Commit 55ed51fff224 ("{tty: serial, nand: onenand}: samsung: rename to
fix build warning") has changed the samsung.c driver to be
samsung_mtd.c in order to avoid a conflict in module names with the
tty driver.

Since the *_mtd suffix is very undescriptive, rename it to
onenand_samsung.c, following the folder's convention. Same will be
applied to the omap2 onenand driver.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

{tty: serial, nand: onenand}: samsung: rename to fix build warning

Any arm config which has 'CONFIG_MTD_ONENAND_SAMSUNG=m' and
'CONFIG_SERIAL_SAMSUNG=m' gives a build warning:

warning: same module names found:
drivers/tty/serial/samsung.ko
drivers/mtd/nand/onenand/samsung.ko

Rename both drivers/tty/serial/samsung.c to
drivers/tty/serial/samsung_tty.c and drivers/mtd/nand/onenand/samsung.c
drivers/mtd/nand/onenand/samsung_mtd.c to fix the warning.

Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/r/20191117202435.28127-1-sudipm.mukherjee@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

mtd: Move onenand code base to drivers/mtd/nand/onenand

Move onenand code base to the drivers/mtd/nand directory in the hope
that someday someone will patch it to use the generic NAND helpers.
If it never happens, at least we'll have all NAND related support in a
single directory and not spread over the drivers/mtd/ directory.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>