nova: update to r6 nova kernel branch

- adds general support for semaphore timeouts
- fixes PCID feature (aka tagged TLB) seeen on Lenovo X201

Fixes #1211
timer: nova specific version of the service

Issue #1211
tcp_terminal: fix run script

Fixes #1210.
Fix race condition in page fault notification

When a page fault cannot be resolved, the GDB monitor can get a hint about
which thread faulted by evaluating the thread state object returned by
'Cpu_session::state()'. Unfortunately, with the current implementation,
the signal which informs GDB monitor about the page fault is sent before
the thread state object of the faulted thread has been updated, so it
can happen that the faulted thread cannot be determined immediately
after receiving the signal.

With this commit, the thread state gets updated before the signal is sent.

At least on base-nova it can also happen that the thread state is not
accessible yet after receiving the page fault notification. For this
reason, GDB monitor needs to retry its query until the state is
accessible.

Fixes #1206.
fixup: "nova: update to r6 nova kernel branch"

Issue #1211
Revert "timer: apply PIT quirk to avoid high cpu load"

This reverts commit edc03489b308dba055957813d296e56aa947a3a0.

Since commit

"timer: nova specific version of the service"

a nova specific timer is used and this quirk is not necessary anymore.

Issue #1211
run: fix parsing of mp_server output test

Until now worked solely for 2 CPU setups. Adjust it to the actual available
number of CPUs.

Issue #1212
x86 vmm: add general multiprocessor support

* repos/ports/include/vmm
 - add support to specify cpu location during vCPU construction
* seoul
 - update to latest seoul branch supporting smp
 - adjust to vmm interface changes
 - vCPUs will be put in a round robin fashion on the available host CPUs,
   beginning with the next CPU after the default (boot) CPU
 - number of vCPUs can be specified in run script
* virtualbox
 - adjust to vmm interface changes
 - uses still one vCPU, placed on default (boot) CPU

Fixes #1212
tool chain: disable -Werror for building GDB

Thanks to @duralog for reporting the issue!

Fixes #1214
gdb_monitor: Support session upgrades

This patch enables the debugging on services that rely on dynamic
session upgrades. For example, nitpicker expects its clients to donate
RAM quota that matches the size of the virtual framebuffer, which might
change during the lifetime of a nitpicker session.
debug_nitpicker.run: adapt to libc VFS changes
ports-foc: retire unmaintained L4Linux examples
fixup "Fix race condition in page fault notification"

ref #1206
hw & arm_v6: fix bug in calculation of kernel SP

For ARMv6, this aspect wasn't updatet to the new kernel-stack
managment that came up with SMP support.

ref #1199