arm64: kvm: Replace hardcoded '1' with SYS_PAR_EL1_F

Now that we have a definition for the 'F' field of PAR_EL1, use that
instead of coding the immediate directly.
Acked-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will@kernel.org>

arch/arm64/kvm/hyp/switch.c

@@ -264,7 +264,7 @@ static bool __hyp_text __translate_far_to_hpfar(u64 far, u64 *hpfar)
 	tmp = read_sysreg(par_el1);
 	write_sysreg(par, par_el1);
 
-	if (unlikely(tmp & 1))
+	if (unlikely(tmp & SYS_PAR_EL1_F))
 		return false; /* Translation failed, back to guest */
 
 	/* Convert PAR to HPFAR format */