Free up sm kernel objects
Free up ec kernel objects (w/o utcb, w/o vCPU)

+ initialize all ec object members to avoid bugs
+ free up memory of fpu objects

- free up of Utcb of normal Ec missing
- free up of vCPU Ec missing
Free up memory of utcb
Free up vCPU ec kernel objects
Free up pd kernel objects
Revoke left over mappings before destruction of pd
Free up left over pte entries of a pd
Remove utcb if ec creation failed

Original Genode commit (a6d2042d5b83730e6c2c0912da5dddfc103a4b75)
Bugfix: avoid assertion by checking sc priority

Kernel fails if Sc priority is higher/equal to the maximum (128 currently)