Update copyright messages
Clean up keypad driver

Merged nspire_keypad_data into struct nspire_keypad.
Deleted unnessecary header.
Added comma to end of .probe = nspire_keypad_probe.
Remove redundant clock-names
Re-enable bus access to some peripherals on bootup
Initialize second sub-timer correctly in timer driver
Clean up nspire-classic-timer code.

Implement a proper nspire_timer_set_mode function
Removed messy IO_MATCHx and CNTL_MATCHx macros
Timer starts disabled to begin with
Interrupt handling code return IRQ_NONE for spurious interrupts
Delete unnessecary shift