vexpress64: fvp dram: add DRAM configuration

Create an additional FVP configuration to boot images pre-loaded into
DRAM.

Sometimes it's preferential to boot the model by loading the files
directly into DRAM via model parameters, rather than using
SemiHosting.

An example of model parmaters that are used to pre-load the files
into DRAM:
    --data cluster0.cpu0=Image@0x80080000 \
    --data cluster0.cpu0=fvp-base-gicv2-psci.dtb@0x83000000 \
    --data cluster0.cpu0=uInitrd@0x84000000

Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
[trini: Update board/armltd/vexpress64/Kconfig logic]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3a336e6..7981355 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -567,6 +567,15 @@
 	select ARM64
 	select SEMIHOSTING
 
+config TARGET_VEXPRESS64_BASE_FVP_DRAM
+	bool "Support Versatile Express ARMv8a FVP BASE model booting from DRAM"
+	select ARM64
+	help
+	  This target is derived from TARGET_VEXPRESS64_BASE_FVP and over-rides
+	  the default config to allow the user to load the images directly into
+	  DRAM using model parameters rather than by using semi-hosting to load
+	  the files from the host filesystem.
+
 config TARGET_VEXPRESS64_JUNO
 	bool "Support Versatile Express Juno Development Platform"
 	select ARM64