History for arm-trusted-firmware / drivers / renesas / rcar / ddr / dram_sub_func.h

Now that DDR drivers are mostly cleaned up , move them out of staging.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Change-Id: I9de63f847a0ef9ac27a79fb0f848c351fd7f4da6