Add sixtron connector Nexus PWM

[Sokario]

A mapping for PWM phandles needs to be defined in the sixtron_connector.dtsi in order to be easily used for pwm specifiers.

zephyr_zest-core-nrf5340/boards/catie/zest_core_nrf5340/sixtron_connector.dtsi

Line 48 in 7a861d1

<DIO18 0 &gpio1 11 0>;

  <DIO18 0 &gpio1 11 0>;
+ 
+ sixtron_connector_1_pwm: sixtron-connector-1-pwm {
+     compatible = "sixtron-pwm";
+     #pwm-cells = <3>;
+     pwm-map-mask = <0xffffffff 0x0 0x0>;
+     pwm-map-pass-thru = <0x0 0xffffffff 0x0f>;
+     pwm-map = <PWM1 0 0 &<PERIPHERAL> <CHANNEL> 0 0>,
+               <PWM2 0 0 &<PERIPHERAL> <CHANNEL> 0 0>,
+               <PWM3 0 0 &<PERIPHERAL> <CHANNEL> 0 0>;
+ }

An example to populate PERIPHERAL and CHANNEL is available here:

pwm-map = <PWM1 0 0 &pwm1 3 0 0>,
          <PWM2 0 0 &pwm1 2 0 0>,
          <PWM3 0 0 &pwm3 3 0 0>;

A label needs to defines the default pwm nexus.

zephyr_zest-core-nrf5340/boards/catie/zest_core_nrf5340/sixtron_connector.dtsi

Line 58 in 7a861d1

sixtron_spi: &sixtron_connector_1_spi {};

  sixtron_spi: &sixtron_connector_1_spi {};
+ sixtron_pwm: &sixtron_connector_1_pwm {};

Caution

Be sure to compile example to validate the nexus.