Remove redundant keyword identifiers (#1140)

The third field of keywords.txt is used to provide Arduino Language
Reference links, which are accessed from the Arduino IDE by
highlighting the keyword and then selecting "Find in Reference"
from the Help or right click menu. Adding values to this field that
do not match any existing reference pages results in a "Could not
open the URL" error.

Author: per1234

keywords.txt

@@ -197,8 +197,8 @@ MY_RFM95_ENABLE_ENCRYPTION	LITERAL1
 # RFM69
 MY_DEBUG_VERBOSE_RFM69	LITERAL1
 MY_DEBUG_VERBOSE_RFM69_REGISTERS	LITERAL1
-MY_IS_RFM69HW	LITERAL1	LITERAL1
-MY_RADIO_RFM69	LITERAL1	LITERAL1
+MY_IS_RFM69HW	LITERAL1
+MY_RADIO_RFM69	LITERAL1
 MY_RFM69_ATC_MODE_DISABLED	LITERAL1
 MY_RFM69_ATC_TARGET_RSSI_DBM	LITERAL1
 MY_RFM69_BITRATE_LSB	LITERAL1