tegra2: Fix default RAM size selection in odmdata

tegra2: Fix default RAM size selection in odmdata

A value of 0 in the odmdata RAM size field means default, which is 512MB
not 1GB. Fix this. For reference, see:

http://nv-tegra.nvidia.com/gitweb/?p=linux-2.6.git;a=blob;\
f=arch/arm/mach-tegra/odm_kit/query/harmony/tegra_devkit_custopt.h;\
h=1ec7010911454f19a5018952fd245785a62c59ad;\
hb=0e52d7fe25b11a656c376a37890be219470661fb

v2: New patch

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>