[flashrom] ft2232_spi JTAGkey OE disabled for CS high

[Ulrich Holeschak]

Hello,
when using the ft2232_spi driver with Amontec JTAGkey, the OE signal 
(bit 4) is disabled
when de-asserting CS:
     msg_pspew("De-assert CS#\n");
     buf[i++] = SET_BITS_LOW;
     buf[i++] = cs_bits;
     buf[i++] = pindir;

This means that the CS high signal is floating and the voltage level is 
unstable.

Filtering the OE bit fixes this issue:
     msg_pspew("De-assert CS#\n");
     buf[i++] = SET_BITS_LOW;
     buf[i++] = cs_bits & 0x0F;    // keep OE active
     buf[i++] = pindir;

Regards,
Ulrich