mfd: qcom-spmi-pmic: Don't access non-existing registers

Revision ID registers are available only on devices with
Slave IDs that are even, so don't make access to unavailable
registers.

Signed-off-by: Ivan T. Ivanov <[e-mail]>
[[e-mail]: Consider all slave ids that are even]
Signed-off-by: Stephen Boyd <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/qcom-spmi-pmic.c

···
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);
 
-	pmic_spmi_show_revid(regmap, &sdev->dev);
+	/* Only the first slave id for a PMIC contains this information */
+	if (sdev->usid % 2 == 0)
+		pmic_spmi_show_revid(regmap, &sdev->dev);
 
 	return of_platform_populate(root, NULL, NULL, &sdev->dev);
 }