arm64: KVM: Remove pgd_lock

The lock has never been used and the page tables are protected by
mmu_lock in struct kvm.
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NSteven Price <steven.price@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@arm.com>

arch/arm64/include/asm/kvm_host.h

@@ -61,8 +61,7 @@ struct kvm_arch {
 	u64    vmid_gen;
 	u32    vmid;
 
-	/* 1-level 2nd stage table and lock */
-	spinlock_t pgd_lock;
+	/* 1-level 2nd stage table, protected by kvm->mmu_lock */
 	pgd_t *pgd;
 
 	/* VTTBR value associated with above pgd and vmid */