Use sysfs GPIO API instead of 'brcm_fw_tool'.

'brcm_fw_tool' cannot be used for controlling GPIOs
in IOP6. In IOP5 we used 'brcm_fw_tool' to setup the
GPIOs for the laser interfaces on the Panther platform.

Because of this the Panther hardware doesn't get a
fiber uplink in IOP6.

iopsys-brcm63xx-arm/panther/base-files/etc/init.d/hw_setup

@@ -7,11 +7,15 @@ boot() {
         # set static gpios
         # one
         for gpio in $(db -q get hw.board.gpio_one); do
-                brcm_fw_tool set -x $gpio -p 1 >/dev/null
+		echo "$gpio" > "/sys/class/gpio/export"
+		echo out > "/sys/class/gpio/gpio${gpio}/direction"
+		echo 1 > "/sys/class/gpio/gpio${gpio}/value"
         done
         # zero
         for gpio in $(db -q get hw.board.gpio_zero); do
-                brcm_fw_tool set -x $gpio -p 0 >/dev/null
+		echo "$gpio" > "/sys/class/gpio/export"
+		echo out > "/sys/class/gpio/gpio${gpio}/direction"
+		echo 0 > "/sys/class/gpio/gpio${gpio}/value"
         done
 }