staging: vt6656: CARDqGetTSFOffset remove camel case

camel case changes
byRxRate -> rx_rate
qwTSF1 -> tsf1
qwTSF2 -> tsf2
qwTSFOffset -> tsf_offset
wRxBcnTSFOffst -> rx_bcn_offset

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>