ARM: at91: gpio: fix at91_set_gpio_value() define

ARM: at91: gpio: fix at91_set_gpio_value() define

When the CONFIG_ATMEL_LEGACY is undefined, according to the following
defines, at91_set_gpio_value() references to at91_set_pio_value(x, y)
with two parameters.
 #define at91_set_gpio_value(x, y)      at91_set_pio_value(x, y)
 #define at91_get_gpio_value(x)         at91_get_pio_value(x)

But there isn't the implementation of at91_set_pio_value(x, y) with
two parameters in U-Boot. This is an error.

Same as at91_get_gpio_value(x) define.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>