KVM: selftests: Replace hardcoded Linux OS id with HYPERV_LINUX_OS_ID

Use HYPERV_LINUX_OS_ID macro instead of hardcoded 0x8100 << 48

Signed-off-by: Vipin Sharma <vipinsh@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20221212183720.4062037-12-vipinsh@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

tools/testing/selftests/kvm/x86_64/hyperv_clock.c

@@ -104,7 +104,7 @@ static void guest_main(struct ms_hyperv_tsc_page *tsc_page, vm_paddr_t tsc_page_
 
 	/* Set Guest OS id to enable Hyper-V emulation */
 	GUEST_SYNC(1);
-	wrmsr(HV_X64_MSR_GUEST_OS_ID, (u64)0x8100 << 48);
+	wrmsr(HV_X64_MSR_GUEST_OS_ID, HYPERV_LINUX_OS_ID);
 	GUEST_SYNC(2);
 
 	check_tsc_msr_rdtsc();