ARM: dts: aspeed: rainier: Remove gpio hog for GPIOP7

Only the pass 1 Ingraham board (Rainier system) had a micro-controller
wired to GPIOP7 on ball Y23. Pass 2 boards have this ball wired to the
heartbeat LED, so remove the hog as this device tree supports pass 2.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20210915214738.34382-5-eajames@linux.ibm.com


Signed-off-by: Joel Stanley <joel@jms.id.au>