arm64: dts: renesas: falcon-cpu: Add GP LEDs

Three general purpose LEDs are provided on the Falcon CPU board.

Connect GP_LED1, GP_LED2, and GP_LED3 to the gpio-leds frameworks as
indicator LEDs.

These LEDs are arranged in a block of four LEDs on the board itself, but
the fourth LED is as yet unidentified.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Link: https://lore.kernel.org/r/20210322172013.1152121-1-kieran.bingham+renesas@ideasonboard.com


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>