Add #pwm-cells to the STM32 PWM binding and dts files. This is to
support have a pwms clients work properly.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
To move forward and remove use of Kconfig in dts files lets just create
SoC specific dtsi files that the boards can include. We also seperate
out the F3 dtsi files into their own dir.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>