Trivial: style fix

make the style checker happy

rumprun: include configs

since global autoconf is removed, we need to manually add
back the kernel config and rumprun_Config

Use sel4runtime for TLS management.

sel4runtime will initilise the TLS for the first thread in the process
(this should not be overridden as it was in entry.c).

Instead of using the nasty trick of de-initialising the TLS with a null
pointer to set variables in remote TLS, we use the tools from
sel4runtime that aren't so destructive to configure the state for libbmk
and to also ensure that the IPC buffer pointer is set on each thread.

The existing tooling for creating and allocating TLS can still be used
as sel4runtime makes no assumptions or changes to the size or layout of
TLS.

THe platform-independant interface for configuring the TLS from
sel4runtime is also used rather than specific implementations for
different architectures.

Split old TLS code into arch specific code

Split clock code into common and arch specific code

seL4: Add new stdio platform support

A rumprun process may be initialised with existing stdio 'pipes' which
consist of circular buffers in shared memory and notification objects
for signalling the availability of data in the buffers.

Remove timer thread, handle in main rump thread

- remove thread that exists just to handle timer interrupts
- signal timer ntfn from pci thread
- wait directly on timer ntfn in bmk_platform_cpu_block

Remove hardware serial from seL4 rumprun platform

Instead, rely on being provided an endpoint to
contact a serial server on.
putc now buffers characters until the buffer is full, a
newline is printed or flush is explicitly called, at this point
it will IPC the serial server to print the contents of the buffer.

Use an ltimer backed by RPC instead of HW timer

Such that we can run multiple rump apps.

seL4: Use new sel4platsupport timer API

sel4: pci_virt_to_mach now use different page size

seL4: Add CAmkES support

seL4: Change to use simple implementation

seL4: Add better timer and device untyped handling

seL4: Fix new thread function definitions

seL4: Add seL4 as a target rumprun platform