tf-a-tftf-main: use 'integration' branch of TF-A by default

Due to the possibility that master branch of TF-A-test may have
some companion changes in integration branch of TF-A, the
'tf-a-tftf-main' job now uses 'integration' branch of TF-A by
default.

Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
Change-Id: I090465835057f59b5e355d3afc6dc4f2519cfbe1
1 file changed