ARM: dts: at91: fix low limit for CPU regulator

Fix low limit for CPU regulator. Otherwise setting voltages lower than
1.125V will not be allowed (CPUFreq will not be allowed to set proper
voltages on proper frequencies).

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-7-claudiu.beznea@microchip.com