Build: Add platform_common_interface target

To represent interfaces provided by all platform code targets (_s, _ns,
_bl2), allowing easier writing of code targeting all three.

Change-Id: I29839a1c8adf9d015177f6e1cf3a470a1edd0051
Signed-off-by: Raef Coles <raef.coles@arm.com>
1 file changed