davinci: Enable DDR_INIT for DA8XX

davinci: Enable DDR_INIT for DA8XX

Commit 6aa4ad8e3820 ("Convert CONFIG_SOC_DA8XX et al to Kconfig")
converted SOC_DA8XX to Kconfig but missed enabling DDR_INIT for
SOC_DA8XX, which broke OMAPL138 to boot.

Commit 2e87980580d0 ("davinci: Fix omapl138_lcdk builds") disabled
DDR_INIT for all DA850 SoCs. This failed all DA850 boards to boot
as ddr is not being initialized.

Enable SYS_DA850_DDR_INIT for DA8XX so that all DA850 and OMAPL138
will have ddr initialized

Fixes: 2e87980580d0 ("davinci: Fix omapl138_lcdk builds")
Fixes: 6aa4ad8e3820 ("Convert CONFIG_SOC_DA8XX et al to Kconfig")
Reported-by: Sekhar Nori <nsekhar@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: David Lechner <david@lechnology.com>
Reviewed-by: Tom Rini <trini@konsulko.com>