runtime: tdx: config: Use the confidential kernel

As we're building a single confidential kernel, we should rely on it
rather than keep using the specific ones for TDX / SEV / SNP.

However, for debugability-sake, let's do this change TEE by TEE.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

src/runtime/config/configuration-qemu-tdx.toml.in

@@ -13,7 +13,7 @@
 
 [hypervisor.qemu]
 path = "@QEMUTDXPATH@"
-kernel = "@KERNELTDXPATH@"
+kernel = "@KERNELCONFIDENTIALPATH@"
 image = "@IMAGETDXPATH@"
 # initrd = "@INITRDPATH@"
 machine_type = "@MACHINETYPE@"