arm64: dts: ti: k3-am642-evm-nand: Rename pinctrl node and gpio-hog names

arm64: dts: ti: k3-am642-evm-nand: Rename pinctrl node and gpio-hog names

Rename the pin mux and gpio-hog node names to match up with binding
rules. This fixes dtbs_check warnings:
'gpmc0-pins-default' does not match any of the regexes: '-pins(-[0-9]+)?$|-pin$', 'pinctrl-[0-9]+'
'gpio0-36' does not match '^(hog-[0-9]+|.+-hog(-[0-9]+)?)$'

While at it, change the phandle name to be consistent with the pinctrl
naming.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20240830113137.3986091-1-nm@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>