x86/virt/tdx: Disable TDX host support when kexec is enabled

TDX host support currently lacks the ability to handle kexec.  Disable TDX
when kexec is enabled.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lore.kernel.org/all/20231208170740.53979-20-dave.hansen%40intel.com

Author: hansendc

arch/x86/Kconfig

@@ -1973,6 +1973,7 @@ config INTEL_TDX_HOST
 	depends on X86_X2APIC
 	select ARCH_KEEP_MEMBLOCK
 	depends on CONTIG_ALLOC
+	depends on !KEXEC_CORE
 	help
 	  Intel Trust Domain Extensions (TDX) protects guest VMs from malicious
 	  host and certain physical attacks.  This option enables necessary TDX