ARM: keystone: k2g: enable micrel and dp83867 phys

Enable micrel and dp83867 phys for K2G Boards in keystone_defconfig
to support Network driver on these boards (K2G ICE and GP EVM).

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>