[MIPS] Alchemy: Fix USB initialization.

This patch fixes a wrong ifdef in the board setup code, leading to the GPIO
pin not being pulled high, and thus the USB switch not being powered at all.

This finishes the rename of CONFIG_USB_OHCI to CONFIG_USB_OHCI_HCD, which
started in 2005 (before 2.6.12-rc2), then probably because things were
working anyway for most people got forgotten.

[Ralf: Paolo's original patch didn't fix the module case, Florian's patch
only fixed MTX1 etc. so this is a combined patch plus some cleanups.]

Cc: Giuseppe Patanè <giuseppe.patane@tvblob.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>