staging:rtl8192u: Rename EEPROM_ChannelPlan - Style

Rename the constant EEPROM_ChannelPlan to EEPROM_CHANNEL_PLAN,
this clears the checkpatch issue with CamelCase naming.

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>