sel4test-driver: Use initialised IO ops

Instead of initialising a new IO mapper interface, we use the
initialised IO ops interface.

Trivial: style fix

make the style checker happy

sel4test-driver: Make different environment types clearer

Changes the 'env' in sel4test-driver to be called driver_env so that it is not confused
with the environment 'env' in the basic tests. To handle this type change we also
explicitly declare implementations that could take an arbitrary environment to take a
'uintptr_t' type that is cast to the known (and hopefully correct) environment type.

Fix missing braces warning

Initialise stack declared ps_io_ops_t to zero

Use ltimer interface in sel4test

- remove all plat specific timer code
- new timers don't need any code added to sel4test!
- also remove plat_copy_serial caps as it is empty for all cases

Fix whitespace

- remove trailing whitespace
- remove double blank lines
- remove blank lines at end of file

Fix licenses

Refactor copy_cap_to_process to libsel4utils

Move this function to libsel4utils

Move dev init caps functions to libsel4platsupport

init_timer_caps and init_serial_caps is functionality that is often used
in other applications so this has been moved to libsel4platsupport to
reduce bitrot.

Clean up seL4test backend

* Clean up the structure of seL4test.
* Make TK1 use the same device as both the
event-timer and wall-clock timer.

SELFOUR-328: add clocktimer for pc99, omap3 & imx6