Samsung Galaxy Tab 3 7.0inch SM-T210/SM-T211
Samsung Galaxy Tab 3 7.0inch SM-T210/SM-T211 is based on Marvell PXA986 SoC, which contains Vivante GC1000 GPU.
No official Cyanogenmod yet, however some people work on updates: http://forum.xda-developers.com/galaxy-tab-3/development-7
Looks like flashing is done with recovery.
Looks like custom kernels are possible, since at least one is in the works.
Samsung source: http://opensource.samsung.com/reception/receptionSub.do?method=sub&sub=F&searchValue=sm-t21
It is a GSM phone.
Marvell Avastar 88W8787 WLAN/Bluetooth/FM Single-Chip SoC
Marvell 3G Modem 88RF833
We won't port to this device since there is no CyanogenMod support for it and adding support for devices from scratch is a huge waste of time. Moreover, without any CyanogenMod device repository available, it is very hard to know what parts are already free software and what parts will need particular work to be replaced. Bottomline: there are other better devices out there that we already have in sight, so we will port to these rather than to the Galaxy Tab 3.
The sprint version seems to be the qualcomm laden LTE one, whereas the marvell one is non-sprint.
However, there might not be a lot of difference to make up to call that "support".
https://www.gsmarena.com/results.php3?mode=tablet&sFreeText=vivante lists other vivante tablets.
https://www.gsmarena.com/results.php3?mode=phone&sFreeText=vivante lists vivante phones.