Introduce build option to override libc

This patch introduces a build option 'OVERRIDE_LIBC' that platforms
can set to override libc from the BL image. The default value is '0'
to keep the library.

Change-Id: I10a0b247f6a782eeea4a0359e30a8d79b1e9e4e1
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
3 files changed