Fix powman powman_configure_wakeup_state and powman_get_power_state

[eightycc]

This PR resolves issues #2506 and #2511:

To conform with SDK usage, powman_get_power_state now returns the complemented contents of field POWMAN_STATE_CURRENT_BITS of the POWMAN STATE register (#2506).

Corrects operation of powman_configure_wakeup_state (#2511):

• Validates that sleep state is one of the P1.x states, and that the wake-up state is one of the P0.x states.
• Correctly validates power manager state transitions while taking into account the current state, the sleep state, and the wake-up state. Validation conforms to section 6.2.3 of the RP2350 datasheet.
• Sets the SEQ_CFG register bits HW_PWRUP_SRAM0 and HW_PWRUP_SRAM1 while taking into account both the sleep state and the wake-up state.

[peterharperuk]

Thanks for fixing our code! I've spent some time staring at it and done some testing with my powman example and I think it makes sense. It fixes the weird situation where you couldn't specify SRAM on in the wakeup state - which never made sense to me.