RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH

RISC-V: KVM: Replace KVM_REQ_HFENCE_GVMA_VMID_ALL with KVM_REQ_TLB_FLUSH

The KVM_REQ_HFENCE_GVMA_VMID_ALL is same as KVM_REQ_TLB_FLUSH so
to avoid confusion let's replace KVM_REQ_HFENCE_GVMA_VMID_ALL with
KVM_REQ_TLB_FLUSH. Also, rename kvm_riscv_hfence_gvma_vmid_all_process()
to kvm_riscv_tlb_flush_process().

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/20250618113532.471448-5-apatel@ventanamicro.com
Signed-off-by: Anup Patel <anup@brainfault.org>