[ARM] 5523/2: Updated ep93xx defconfig

Updated defconfig for ep93xx. By default, support for all boards which
boot from 0x00000000 (SDCE3/SyncBoot) is included. Also updated the
defconfig to use EABI for building the kernel.
Signed-off-by: NRyan Mallon <ryan@bluewatersys.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>