x86/hyperv/vtl: Add noop for realmode pointers

Assign the realmode pointers to noop, instead of NULL to fix kernel panic.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1682331016-22561-1-git-send-email-ssengar@linux.microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>

arch/x86/hyperv/hv_vtl.c

@@ -20,6 +20,8 @@ void __init hv_vtl_init_platform(void)
 {
 	pr_info("Linux runs in Hyper-V Virtual Trust Level\n");
 
+	x86_platform.realmode_reserve = x86_init_noop;
+	x86_platform.realmode_init = x86_init_noop;
 	x86_init.irqs.pre_vector_init = x86_init_noop;
 	x86_init.timers.timer_init = x86_init_noop;