regulator: stpmic1: Fix USB IRQ handler initialization

Fix USB IRQ handler initialization.
Setting always-on on boost regulator generates a fault.

Unable to handle kernel NULL pointer dereference at virtual address 0000004c
pgd = 54d71286
[0000004c] *pgd=00000000
Internal error: Oops: 5 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 72 Comm: irq/70-pmic_irq Not tainted 5.15.67ppav4.0 torvalds#188
Hardware name: STM32 (Device Tree Support)
PC is at blocking_notifier_call_chain+0x4/0x90
LR is at regulator_notifier_call_chain+0xc/0x14
...
(blocking_notifier_call_chain) from [<c062b368>] (regulator_notifier_call_chain+0xc/0x14)
(regulator_notifier_call_chain) from [<c0644a9c>] (stpmic1_boost_irq_handler+0x4c/0x84)
(stpmic1_boost_irq_handler) from [<c017fbc0>] (handle_nested_irq+0xc8/0x12c)
(handle_nested_irq) from [<c07160b0>] (regmap_irq_thread+0x46c/0x6d4)
(regmap_irq_thread) from [<c017c2dc>] (irq_thread_fn+0x1c/0x7c)
(irq_thread_fn) from [<c017c0bc>] (irq_thread+0x150/0x224)
(irq_thread) from [<c0147874>] (kthread+0x14c/0x164)
(kthread) from [<c0100130>] (ret_from_fork+0x14/0x24)

Signed-off-by: Pascal Paillet <p.paillet@st.com>
Change-Id: I23d72d24d2de029c516f4568dc518917cb2b95ca
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/312297
Reviewed-by: Patrick DELAUNAY <patrick.delaunay@foss.st.com>
ACI: CITOOLS <MDG-smet-aci-reviews@list.st.com>
ACI: CIBUILD <MDG-smet-aci-builds@list.st.com>
Domain-Review: Patrick DELAUNAY <patrick.delaunay@foss.st.com>

drivers/regulator/stpmic1_regulator.c

@@ -722,6 +722,8 @@ stpmic1_boost_register(struct platform_device *pdev, int id,
 		return rdev;
 	}
 
+	usb_data->boost_rdev = rdev;
+
 	/* setup an irq handler for over-current detection */
 	irq = of_irq_get(config.of_node, 0);
 	if (irq > 0) {
@@ -763,8 +765,6 @@ static int stpmic1_regulator_probe(struct platform_device *pdev)
 			stpmic1_boost_register(pdev, i, &stpmic1_matches[i],
 					       &stpmic1_regulator_cfgs[i],
 					       usb_data);
-
-			usb_data->boost_rdev = rdev;
 		} else {
 			rdev =
 			stpmic1_regulator_register(pdev, i, &stpmic1_matches[i],