rw6xx: Add Support for Standby Power Mode

[mmahadevan108]

This maps to Power Mode 3 in the SoC Power Profile

This PR is dependent on #74371 and #84938

[mmahadevan108]

Push a commit from #74371 to fix CI failures.

[bjarki-andreasen]

pm_device_driver_init() must be added to the end of mcux_flexcomm_init(), and will call TURN_ON, potentially followed by resume. Once pm_device_driver_init() is added, calling init here will result in infinite recursion.

the mcux_flexcomm_init() should only be called once, on init, and later reinits are a result of calls to mcux_flexcomm_pm_action()

[mmahadevan108]

@bjarki-andreasen, thank you. I have made the change to call pm_device_driver_init()

[bjarki-andreasen]

pm_device_driver_init() must be added to the gpio_mcux_lpc and uart_mcux_flexcomm init functions to properly initialize the devices. This has further implications which will be clear once pm_device_driver_init() is added.

[mmahadevan108]

@bjarki-andreasen , can you please revisit this PR?

[bjarki-andreasen]

Looks fine, added a note regarding some code which could be a bit simpler, but it will not have any impact once compiled :)

[bjarki-andreasen]

None of these are supported, so should also return -ENOTSUP, can be simplified to

if (action == PM_DEVICE_ACTION_TURN_ON) {
        const struct gpio_mcux_lpc_config *config = dev->config;

	GPIO_PortInit(config->gpio_base, config->port_no);
	return 0;
}

return -ENOTSUP;

[bjarki-andreasen]

This variable is not used outside the scope of mcux_flexcomm_pm_action, move it inside, also does not need to be static