Revert "power: supply: qcom_battmgr: Register the power supplies after PDR is up"

This reverts commit b43f7ddc.

The offending commit deferred power-supply class device registration
until the service-started notification is received.

This triggers a NULL pointer dereference during boot of the Lenovo
ThinkPad X13s and SC8280XP CRD as battery status notifications can be
received before the service-start notification:

	Unable to handle kernel NULL pointer dereference at virtual address 00000000000005c0
	...
	Call trace:
	 _acquire+0x338/0x2064
	 acquire+0x1e8/0x318
	 spin_lock_irqsave+0x60/0x88
	 _supply_changed+0x2c/0xa4
	 battmgr_callback+0x1d4/0x60c [qcom_battmgr]
	 pmic_glink_rpmsg_callback+0x5c/0xa4 [pmic_glink]
	 qcom_glink_native_rx+0x58c/0x7e8
	 qcom_glink_smem_intr+0x14/0x24 [qcom_glink_smem]
	 __handle_irq_event_percpu+0xb0/0x2d4
	 handle_irq_event+0x4c/0xb8

As trying to serialise this is non-trivial and risks missing
notifications, let's revert to registration du...