trivial: Style changed files

trivial: Update licenses

All of these files saw significant changes, so we update the license to
reflect this.

libplatsupport,imx: Move HW ops to driver level

Timer resource initialisation and the management of interrupts should
belong in the driver level and not the timer abstraction level. This
commits moves those operations down into the driver level for the i.MX
platforms.

libplatsupport: Select imx mach drivers by plat

The mach folders contain shared drivers for all platforms with the same
"KernelArmMach" type. Making subdirectories allows for more fine grained
control of source file includes to handle situations when one or more
platforms don't use the shared devices but are still of the same mach.