arm64: dts: qcom: sdm845-shift-axolotl: describe WiFi/BT properly

arm64: dts: qcom: sdm845-shift-axolotl: describe WiFi/BT properly

The onboard WiFi / BT device, WCN3990, has a simple on-chip PMU, which
further spreads generated voltage. Describe the PMU in the device tree.

Signed-off-by: David Heidelberg <david@ixit.cz>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260415-axolotl-wifi-v1-1-07df39cfc0a4@ixit.cz
Signed-off-by: Bjorn Andersson <andersson@kernel.org>