arm: omap: emif-common: Fix memory priming for ECC

Before the priming begins, we need to disable RMW (Read Modify Write)
and disable ECC verification for read accesses. By default, the EMIF
tool enables RMW and read accesses in the EMIF_ECC_CTRL_REG.

Signed-off-by: Krunal Bhargav <k-bhargav@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>