ath9k_hw: Cleanup eeprom_9287.c

* Fix whitespace damage.
* Remove unused debug messages.
* Introduce a macro NUM_EEP_WORDS.
* Convert AR9287 to lowercase in function names.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>