staging: wilc1000: use defines for msg types received from firmware

Added defines for different types of messages received from firmware.
Removed the unnecessary comments because after the addition of macros
the message types are self-explanatory.

Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
Link: https://lore.kernel.org/r/20191105095058.24223-7-ajay.kathat@microchip.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>