KVM: x86: Drop pointless exports of kvm_arch_xxx() hooks

Drop the exporting of several kvm_arch_xxx() hooks that are only called
from arch-neutral code, i.e. that are only called from kvm.ko.

Link: https://lore.kernel.org/r/20250919003303.1355064-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Author: sean-jc

arch/x86/kvm/x86.c

@@ -13922,14 +13922,12 @@ void kvm_arch_register_noncoherent_dma(struct kvm *kvm)
 	if (atomic_inc_return(&kvm->arch.noncoherent_dma_count) == 1)
 		kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
-EXPORT_SYMBOL_GPL(kvm_arch_register_noncoherent_dma);
 
 void kvm_arch_unregister_noncoherent_dma(struct kvm *kvm)
 {
 	if (!atomic_dec_return(&kvm->arch.noncoherent_dma_count))
 		kvm_noncoherent_dma_assignment_start_or_stop(kvm);
 }
-EXPORT_SYMBOL_GPL(kvm_arch_unregister_noncoherent_dma);
 
 bool kvm_arch_has_noncoherent_dma(struct kvm *kvm)
 {
@@ -13941,7 +13939,6 @@ bool kvm_arch_no_poll(struct kvm_vcpu *vcpu)
 {
 	return (vcpu->arch.msr_kvm_poll_control & 1) == 0;
 }
-EXPORT_SYMBOL_GPL(kvm_arch_no_poll);
 
 #ifdef CONFIG_KVM_GUEST_MEMFD
 /*