RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()

When the host has Svpbmt extension, we should use page based memory
type 2 (i.e. IO) for IO mappings in the G-stage page table.

To achieve this, we replace use of PAGE_KERNEL with PAGE_KERNEL_IO
in the kvm_riscv_gstage_ioremap().
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

arch/riscv/kvm/mmu.c

@@ -361,7 +361,7 @@ int kvm_riscv_gstage_ioremap(struct kvm *kvm, gpa_t gpa,
 	pfn = __phys_to_pfn(hpa);
 
 	for (addr = gpa; addr < end; addr += PAGE_SIZE) {
-		pte = pfn_pte(pfn, PAGE_KERNEL);
+		pte = pfn_pte(pfn, PAGE_KERNEL_IO);
 
 		if (!writable)
 			pte = pte_wrprotect(pte);