mb/google/poppy: Rework OV13858 power on sequence

In particular:

- Set voltage before enabling regulators

- Enable regulators and the clock without any sleeping in between. There's
  no need to wait there.

- Sleep 1 ms in order to wait for regulator voltages settling before
  lifting xshutdown.

BUG=chromium:959232

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Jacopo Mondi <jacopo@jmondi.org>
Change-Id: I0f8857ae369d5038f293a0e2c48c681df535ad86
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36744
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/mainboard/google/poppy/variants/baseboard/include/baseboard/acpi/camera_pmic.asl

@@ -468,23 +468,33 @@ Scope (\_SB.PCI0.I2C2)
 							C0GP = 1
 						}
 
-						VACT = 1
 						if (LNotEqual (ACVA, 109)) {
 							/* Set ANA at 2.8152V */
 							ACVA = 109
 						}
-						Sleep(3)
+						VACT = 1
 
-						\_SB.PCI0.I2C2.PMIC.CLKE()
-						CLE0 = 1
-
-						VDCT = 1
 						if (LNotEqual (DCVA, 12)) {
 							/* Set CORE at 1.2V */
 							DCVA = 12
 						}
-						Sleep(3)
+						VDCT = 1
+
+						\_SB.PCI0.I2C2.PMIC.CLKE()
+						CLE0 = 1
+
+						/*
+						 * Wait for all regulator
+						 * outputs to settle.
+						 */
+						Sleep(1)
+
 						\_SB.PCI0.I2C2.PMIC.CRST(1)
+
+						/*
+						 * 5 ms needed before
+						 * streaming on.
+						 */
 						Sleep(5)
 
 						STA = 1