ARM: dts: at91: calao_usb: simplify memory node

All devices have 64MB RAM. So, the memory node can be put into the
most generic DTSI.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20250402204856.5197-2-wsa+renesas@sang-engineering.com


[claudiu.beznea: s/can bet put/can be put/g in commit description]
Signed-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>