Different A83T boards have different DRAM types. Banapi M3 has LPDDR3,
Allwinner Homlet v1.2 has DDR3.

This adds groundwork to support for new DRAM type for A83T.

Introduce CONFIG_DRAM_TYPE, It'll be 3 for DDR3 and 7 for LPDDR3, must
be set in respective board defconfig.

Signed-off-by: Vishnu Patekar <vishnupatekar0510@gmail.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>