configs: omap3/35_logic and omap3/35_logic_somlv: Reduce SPL size

Currently the DM37 and OMAP35 boards do not boot due to SPL
bring too large.

SPL doesn't need GPIO, I2C nor MMC sector access since it uses
a FAT file system.

This patch unifies all these boards to remove these unused features
from their defconfigs

Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>