dt-bindings: net: ethernet-controller: fix typo in NVMEM

stable inclusion
from stable-5.10.30
commit 982dd14fba0f4e0007ecbe260e2d89e83c701847
bugzilla: 51791

--------------------------------

commit af9d316f upstream.

The correct property name is "nvmem-cell-names". This is what:
1. Was originally documented in the ethernet.txt
2. Is used in DTS files
3. Matches standard syntax for phandles
4. Linux net subsystem checks for

Fixes: 9d3de3c5 ("dt-bindings: net: Add YAML schemas for the generic Ethernet options")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by:   Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>