soc: nordic: nrf54h: Allow using NFCT pins as gpios on cpurad

NFCT is by default assigned to application so DT node does
not need to be enabled or reserved in DT to have access to
NFCT registers. On cpurad NFCT must be reserved to enable
register access and then antenna pins can be configured as
gpios.

Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>