init_moto_msm8960: Add support for C Spire Photon Q

- surprisingly, the difference seems not to be in androidboot.carrier
(for both Sprint and C Spire devices it's set to 'sprint' ?!) but in
androidboot.modelno - C Spire variant sets it to 'XT897', while it's
missing in the Sprint case...

Change-Id: Ib09ddf052202cd5e3b62f050bc82d5502b118fc9
Merge "init_moto_msm8960: Add support for C Spire Photon Q" into cm-11.0
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_motorola_moto_msm8960 into cd-4.4