Add writable test for the ID_AA64PFR1_EL1 register.
Signed-off-by: Shaoqin Huang <shahuang@redhat.com>
Link: https://lore.kernel.org/r/20240723072004.1470688-5-shahuang@redhat.comSigned-off-by: Marc Zyngier <maz@kernel.org>