ARM: dts: at91: sama7g5: fix signal name of pin PD8

The signal name of pin PD8 with function D is A22_NANDCLE
as it is defined in the datasheet.

Signed-off-by: Mihai Sain <mihai.sain@microchip.com>
[claudiu.beznea: rebased on top of 6.1-rc1, removed fixes tag]
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20221114151035.2926-1-mihai.sain@microchip.com