dt-bindings: rtc: mpfs-rtc: Properly name file

The actual compatible string is microchip,mpfs-rtc, not microchip,mfps-rtc.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20241011100608.862428-1-alexandre.belloni@bootlin.com


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>