ARM: keystone2: use SPD info to configure K2HK and K2E DDR3

This commit replaces hard-coded EMIF and PHY DDR3 configurations for
predefined SODIMMs to a calculated configuration. The SODIMM parameters
are read from SODIMM's SPD and used to calculated the configuration.

The current commit supports calculation for DDR3 with 1600MHz and 1333MHz
only.

Signed-off-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>