Exynos: Avoid a divide by zero by specifying a non-zero period for pwm 4

Exynos: Avoid a divide by zero by specifying a non-zero period for pwm 4

The pwm_config function in the exynos pwm driver divides by its period
period parameter. A function was calling pwm_config with a 0ns period and a
0ns duty cycle. That doesn't actually make any sense physically, and results
in a divide by zero in the driver. This change changes the parameters to be a
100000ns period and duty cycle.

Test with command "sf probe 1:0; time sf read 40008000 0 1000".
Try with different numbers of bytes and see that sane values are obtained
Build and boot U-boot with this patch, backlight works properly.

Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Akshay Saraswat <akshay.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>