SRV_Channels: stop gating FETTECONEWIRE parameters on HAL_BUILD_BUILD_AP_PERIPH

This would break fettech on AP_Periph.  The define is off by default on
AP_Periph.

libraries/SRV_Channel/SRV_Channels.cpp

@@ -214,16 +214,12 @@ const AP_Param::GroupInfo SRV_Channels::var_info[] = {
     AP_SUBGROUPINFO(robotis, "_ROB_",  22, SRV_Channels, AP_RobotisServo),
 #endif
 
-#ifndef HAL_BUILD_AP_PERIPH
-
 #if AP_FETTEC_ONEWIRE_ENABLED
     // @Group: _FTW_
     // @Path: ../AP_FETtecOneWire/AP_FETtecOneWire.cpp
     AP_SUBGROUPINFO(fetteconwire, "_FTW_",  25, SRV_Channels, AP_FETtecOneWire),
 #endif
 
-#endif // HAL_BUILD_AP_PERIPH
-
     // @Param: _DSHOT_RATE
     // @DisplayName: Servo DShot output rate
     // @Description: This sets the DShot output rate for all outputs as a multiple of the loop rate. 0 sets the output rate to be fixed at 1Khz for low loop rates. This value should never be set below 500Hz.