Use new driver debug macros

This is in preparation for moving the debug argument from driver to device.
New macros:
* fbtft_par_dbg() - Used in FBTFT operations
* fbtft_init_dbg() - used in probe() and remove()

Remove debug ouput from module init/exit.
move 'debug' argument from driver to device

Also add 'debug' argument to fbtft module. This way it's possible to turn on
debugging during boot if the modules is built-in.
remove empty debug macros
fbtft: change debug macros

Use fbtft_par_dbg where possible.
Change macro name: fbtft_fbtft_dev_dbg -> fbtft_dev_dbg
Fix 2 places where debug hex output was missing.
fbtft: fix hex debug output function