RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()

RISC-V: KVM: Rename and move kvm_riscv_local_tlb_sanitize()

The kvm_riscv_local_tlb_sanitize() deals with sanitizing current
VMID related TLB mappings when a VCPU is moved from one host CPU
to another.

Let's move kvm_riscv_local_tlb_sanitize() to VMID management
sources and rename it to kvm_riscv_gstage_vmid_sanitize().

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Nutty Liu <liujingqi@lanxincomputing.com>
Link: https://lore.kernel.org/r/20250618113532.471448-4-apatel@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>