openocd: Add Artix DC-SCM cable type

The Antmicro Artix DC-SCM uses the following FTDI part:

 0403:6011 Future Technology Devices International, Ltd FT4232H Quad HS USB-UART/FIFO IC

To use:

 $ openocd/flash-arty -c antmicro-artix-dc-scm -f a100 -t bin -a 0x300000 ~/u-boot

Signed-off-by: Joel Stanley <joel@jms.id.au>

openocd/antmicro-artix-dc-scm.cfg

@@ -0,0 +1,6 @@
+interface ftdi
+ftdi_vid_pid 0x0403 0x6011
+ftdi_channel 0
+ftdi_layout_init 0x00e8 0x60eb
+reset_config none
+adapter_khz 25000