mtd: rawnand: meson: fix scrambling mode value in command macro

Scrambling mode is enabled by value (1 << 19). NFC_CMD_SCRAMBLER_ENABLE
is already (1 << 19), so there is no need to shift it again in CMDRWGEN
macro.

Signed-off-by: Arseniy Krasnov <avkrasnov@salutedevices.com>
Cc: <Stable@vger.kernel.org>
Fixes: 8fae856c ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240210214551.441610-1-avkrasnov@salutedevices.com