Hey @zjor,
BldcDriver6pwm is not intended for that. Do not use that one.
The infineon shields need only 3 pwm signals and 3 enable signals.
You have two choices really:
1)provide 1 enable to BLDCDriver3pwm and 2 of them enable in the setup function:
void setup(){
...
digitalWrite(INH2, HIGH);
digitalWrite(INH3, HIGH);
...
}
- use the dev version of the library which has implemented already this feature. You can provide them at the same time to the BLDCMotor3PWM:
BLDCMotor3PWM (IN1,IN2, IN3, INH1,INH2, INH3)
The dev version is not yet documented well and it has some changements in the api (just a bit in your case) so its up to you. 
But this will be a standard feature from the next release. (Next week)