set target cpu variant for vexpress devices

TARGET_CPU_VARIANT is set to "cortex-a15" for Juice and
"cortex-a9" for rest of the builds e.g TC2, VE-A9, MP.. for the time being.

Change-Id: Id8aec969298bdf94b34ab5b9ff7ea8f7e6fd94bf
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
1 file changed