MIPS: Fuloong 2E: Replace CONFIG_USB_ISP1760_HCD by CONFIG_USB_ISP1760

Since commit 100832ab

 ("usb: isp1760: Make HCD support
optional"), CONFIG_USB_ISP1760_HCD is automatically selected when
needed.  Enabling that option in the defconfig is now a no-op, and no
longer enables ISP1760 HCD support.

Re-enable the ISP1760 driver in the defconfig by enabling
USB_ISP1760_HOST_ROLE instead.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10180/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>