dt-bindings: clocks: atmel,at91sam9x5-sckc: add sam9x7

Add bindings for SAM9X7's slow clock controller.

Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>
Link: https://lore.kernel.org/r/20240729070717.1990654-1-varshini.rajendran@microchip.com


Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>