[ Upstream commit 2ab78755 ]

The default word_size and stride of 1 are correct for the tx4939. Also fix
the nvmem folder name.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>