RISC-V: KVM: use kvm_trylock_all_vcpus when locking all vCPUs

RISC-V: KVM: use kvm_trylock_all_vcpus when locking all vCPUs

Use kvm_trylock_all_vcpus instead of a custom implementation when locking
all vCPUs of a VM.

Compile tested only.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Tested-by: Anup Patel <anup@brainfault.org>
Message-ID: <20250512180407.659015-7-mlevitsk@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>