arm64: Convert HPFAR_EL2 to sysreg table

Switch over to the typical sysreg table for HPFAR_EL2 as we're about to
start using more fields in the register.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250402201725.2963645-3-oliver.upton@linux.dev


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>