UefiCpuPkg: RISC-V: Support MMU with SV39/48/57 mode

During CpuDxe initialization, MMU will be setup with the highest
mode that HW supports.

Signed-off-by: Tuan Phan <tphan@ventanamicro.com>
Reviewed-by: Andrei Warkentin <andrei.warkentin@intel.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>

UefiCpuPkg/Library/BaseRiscVMmuLib/RiscVMmuCore.S

@@ -0,0 +1,31 @@
+/** @file
+*
+*  Copyright (c) 2023, Ventana Micro Systems Inc. All Rights Reserved.<BR>
+*
+*  SPDX-License-Identifier: BSD-2-Clause-Patent
+*
+**/
+
+#include <Base.h>
+#include <Register/RiscV64/RiscVImpl.h>
+
+.text
+  .align 3
+
+//
+// Local tlb flush all.
+//
+//
+ASM_FUNC (RiscVLocalTlbFlushAll)
+sfence.vma
+ret
+
+//
+// Local tlb flush at a virtual address
+// @retval a0 : virtual address.
+//
+ASM_FUNC (
+  RiscVLocalTlbFlush
+  )
+sfence.vma a0
+ret