Platform/RaspberryPi: don't connect all devices on an ordinary boot

The BDS will connect device paths that are considered as boot options,
so there is really no reason to always connect absolutely everything.
So now that all the drivers have been updated to play nice in this
case, remove the ConnectAll() call from the RPi BDS code.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Reviewed-by: Pete Batard <pete@akeo.ie>
Tested-by: Pete Batard <pete@akeo.ie>
Acked-by: Leif Lindholm <leif@nuviainc.com>