x86/virt/tdx: Refresh TDX module version after update

x86/virt/tdx: Refresh TDX module version after update

The kernel exposes the TDX module version through sysfs so userspace
can check update compatibility. That information needs to remain
accurate across runtime updates.

A runtime update may change the module's update_version, so refresh
the cached version right after a successful update.

Drop __ro_after_init from tdx_sysinfo because it is now updated at
runtime.

Do not refresh the rest of tdx_sysinfo, even if some values change
across updates. TDX module updates are backward compatible, so
existing tdx_sysinfo consumers, such as KVM, can continue to operate
without seeing the new values.

[ dhansen: trim changelog ]

Signed-off-by: Chao Gao <chao.gao@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://patch.msgid.link/20260520133909.409394-22-chao.gao@intel.com