MIPS: ralink: Drop obsolete USB_ARCH_HAS_HCD select

Building an allnoconfig kernel based on the ralink platform results in
the following warning:

warning: (SOC_RT305X) selects USB_ARCH_HAS_HCD which has unmet direct dependencies (USB_SUPPORT)

This is because SOC_RT305X unconditionally selects USB_ARCH_HAS_HCD
which depends on USB_SUPPORT.

However USB_ARCH_HAS_HCD has been effectively obsolete since commit
d9ea21a7 ("usb: host: make USB_ARCH_HAS_?HCI obsolete") in 3.11.
USB_ARCH_HAS_HCD is now set by default whenever USB_SUPPORT is, so drop
the select to silence the warning.

Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17618/