Rename fields in the struct wrsSpllVersionGroup_s to reflect SNMP objects'
names.

index -> wrsPtpDataIndex
port_name -> wrsPtpPortName
gm_id -> wrsPtpGrandmasterID
my_id -> wrsPtpOwnID
ppsi_mode -> wrsPtpMode
servo_state_name -> wrsPtpServoState
servo_state -> wrsPtpServoStateN
tracking_enabled -> wrsPtpPhaseTracking
sync_source -> wrsPtpSyncSource
clock_offset -> wrsPtpClockOffsetPs
clock_offsetHR -> wrsPtpClockOffsetPsHR
skew -> wrsPtpSkew
rtt -> wrsPtpRTT
llength -> wrsPtpLinkLength
servo_updates -> wrsPtpServoUpdates
delta_tx_m -> wrsPtpDeltaTxM
delta_rx_m -> wrsPtpDeltaRxM
delta_tx_s -> wrsPtpDeltaTxS
delta_rx_s -> wrsPtpDeltaRxS
n_err_state -> wrsPtpServoStateErrCnt
n_err_offset -> wrsPtpClockOffsetErrCnt
n_err_delta_rtt -> wrsPtpRTTErrCnt
update_time -> wrsPtpServoUpdateTime
Signed-off-by: Adam Wujek <adam.wujek@cern.ch>