wifi: ath12k: Power up root PD

Q6 processor acts as rootPD, other hardware like IPQ5332 which are
attached to Q6 act as userPDs. WCSS driver handles loading and booting
of rootPD, while the ath12k driver boots the userPD.
Get the rproc handle from the DTS entry and boot the rootPD if it
is not already powered on. Register to the rproc notifier to monitor
the rproc state, this allows ath12k driver to know power up/down
sequence of the rootPD. Power up the rootPD and wait for a power-up
notification from the notifier callback before powering up the userPDs.

Tested-on: IPQ5332 hw1.0 AHB WLAN.WBE.1.3.1-00130-QCAHKSWPL_SILICONZ-1

Signed-off-by: Sowmiya Sree Elavalagan <quic_ssreeela@quicinc.com>
Reviewed-by: Vasanthakumar Thiagarajan <vasanthakumar.thiagarajan@oss.qualcomm.com>
Co-developed-by: Raj Kumar Bhagat <quic_rajkbhag@quicinc.com>
Signed-off-by: Raj Kumar Bhagat <quic_rajkbhag@quicinc.com>
Link: https://patch.msgid.link/20250321-ath12k-ahb-v12-9-bb389ed76ae5@quicinc.com


Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>