Add nvs support to nucleo_f091rc board. This requires to
add erase-block-size property to stm32f0.dtsi.
Storage partition is set to 4kb at the end of the flash.
Signed-off-by: Erwan Gouriou <erwan.gouriou@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 F0 dtsi files into their own dir.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>