platform: msm_shared: Fix UFS serial number calculation

UFS serial number is calculated by adding the unicode string received
from the device, due to this probability serial number being same across
devices is more due to number collision. Change the serial number
calculation logic to use crc32 calculation on unicode serial number read
from device to make sure the collision is avoided and we get a unique
serial number across devices.

Change-Id: I201ffbb0d9f495de644b0741ebe0f243d1a6b5c2
4 files changed