ram: octeon: Add MIPS Octeon3 DDR4 support (part 3/3)

This Octeon 3 DDR driver is ported from the 2013 Cavium / Marvell U-Boot
repository. It currently supports DDR4 on Octeon 3. It can be later
extended to support also DDR3 and Octeon 2 platforms.

Part 3 includes the DIMM SPD handling code and the Kconfig / Makefile
integration.

Signed-off-by: Aaron Williams <awilliams@marvell.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/drivers/ram/Kconfig b/drivers/ram/Kconfig
index 7e6e981..a0e859a 100644
--- a/drivers/ram/Kconfig
+++ b/drivers/ram/Kconfig
@@ -76,3 +76,4 @@
 source "drivers/ram/rockchip/Kconfig"
 source "drivers/ram/sifive/Kconfig"
 source "drivers/ram/stm32mp1/Kconfig"
+source "drivers/ram/octeon/Kconfig"