staging:rtl8192u: Rename EEPROM_Default_TxPower - Style

rename the constant EEPROM_Default_TxPower to EEPROM_DEFAULT_TX_POWER,
this clears the checkpatch issue with CamelCase issue.

This is purely a coding style change which should have no impact
on runtime code execution.

Signed-off-by: John Whitmore <johnfwhitmore@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>