coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/

coco/guest: Move shared guest CC infrastructure to drivers/virt/coco/guest/

In preparation for creating a new drivers/virt/coco/host/ directory to
house shared host driver infrastructure for confidential computing, move
configfs-tsm to a guest/ sub-directory. The tsm.ko module is renamed to
tsm_reports.ko. The old tsm.ko module was only ever demand loaded by
kernel internal dependencies, so it should not affect existing userspace
module install scripts.

The new drivers/virt/coco/guest/ is also a preparatory landing spot for
new / optional TSM Report mechanics like a TCB stability enumeration /
watchdog mechanism. To be added later.

Cc: Wu Hao <hao.wu@intel.com>
Cc: Yilun Xu <yilun.xu@intel.com>
Cc: Samuel Ortiz <sameo@rivosinc.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Alexey Kardashevskiy <aik@amd.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://patch.msgid.link/174107246641.1288555.208426916259466774.stgit@dwillia2-xfh.jf.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>