x86: broadwell: gpio: Remove the codes to set up pin control

Now that we have set up pin control in cpu_init_r(), remove the
duplicated codes in the broadwell gpio driver.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>