am33xx evm: Update secure_emif_sdram_config during ddr init

am33xx evm: Update secure_emif_sdram_config during ddr init

This patch updates secure_emif_sdram_config with the
same value written to sdram_config during ddr3 initialization.

During suspend/resume, this value is copied into sdram_config.
With this, a write to sdram_config at the end of resume sequence
which triggers an init sequence can be avoided.

Without this register write in place, the DDR_RESET line goes
low for a few cycles during resume which is a violation of the
JEDEC spec.

Signed-off-by: Satyanarayana, Sandhya <sandhya.satyanarayana@ti.com>