at91: ohci-at91: always provide all the clocks

Remove the cpu_is_at91xxxx() macros in the ohci-at91 driver.
SoCs at91sam9261 and at91sam9g10 expect one additional clock: hck0.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>