Blackfin: clean up isp1362 board resources

Drop the CONFIG_USB_ISP1362_BFIN_GPIO_IRQ Kconfig as it never made it into
mainline and it was a bad interface into the board resources.  For boards
that actually used this, replace it with an actual IRQ define.  For boards
that didn't, simply drop the resources.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>