ARMV7: OMAP: Configure Overo's second network chip

Confiures GPMC timings for both chips and also configures pinmux
for GPIO_65, which is used as the interrupt signal for the second chip

Signed-off-by: Scott Ellis <scott@jumpnowtek.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>