dev : pmic : add helper function for pmi8950 pon reason

Check for USB In / DC In bits of the PON register for PMI8950.
8952 Based targets uses PMI8950, hence add an API to return
the appropriate PON reason.

Change-Id: I01b2df4909f7fef45ae5aa1ea2591ce893ea3f0d
diff --git a/dev/pmic/pm8x41/include/pm8x41.h b/dev/pmic/pm8x41/include/pm8x41.h
index 6e89f57..9278470 100644
--- a/dev/pmic/pm8x41/include/pm8x41.h
+++ b/dev/pmic/pm8x41/include/pm8x41.h
@@ -9,7 +9,7 @@
  *     copyright notice, this list of conditions and the following
  *     disclaimer in the documentation and/or other materials provided
  *     with the distribution.
- *   * Neither the name of The Linux Foundation, Inc. nor the names of its
+ *   * Neither the name of The Linux Foundation, nor the names of its
  *     contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
@@ -225,6 +225,7 @@
 int pm8x41_ldo_control(struct pm8x41_ldo *ldo, uint8_t enable);
 uint8_t pm8x41_get_pmic_rev();
 uint8_t pm8x41_get_pon_reason();
+uint8_t pm8950_get_pon_reason();
 uint8_t pm8x41_get_pon_poff_reason1();
 uint8_t pm8x41_get_pon_poff_reason2();
 uint32_t pm8x41_get_pwrkey_is_pressed();