marvell: drivers: Add thermal driver

Add thermal driver for A8K SoC family.
The termal unit data is used by Marvell DRAM initialization
code for optimizing the memory controller configuration

Change-Id: Iad92689fa6e4224a89d872e9aa015393abd9cf73
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>