Use internal stdint and stddef

This changes sel4runtime to use the internal minimal stdint and stddef
removing the dependency for those files from an external libc.

This also removes the imports and dependencies for stdbool, string, and
assert.

Signed-off-by: Curtis Millar <curtis@curtism.me>

Trivial: style fix

make the style checker happy

fix various including problem

1: replace quote includes with bracket includes
2: add missing kernel autoconf
3: remove one unused include

Update licence dates.

Make thread methods publically available.

Make access to thread ID registers publically inlineable.

Add function to set tls_base of current thread.

Clarify use of registers in ARMv6

The function to write to tpidr_el0 should not exist for ARMv6.

Refer to public version of thread_arch.h

Use new TLS base function.

Clarify the ARMv6 requirements.

Remove additional endif.

Make set_tls_base always succeed.

sel4runtime_tls_base -> sel4runtime_get_tls_base

Fix sel4runtime rename in aarch32