Export compiler path in CppCheck & FoorPrint

CppCheck & FootPrint also need to use GCC v7.3.1.
Export PATH to GCC v7.3.1 in these jobs.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: Iab24eb1311c53f5d071eb3208dc1345fa67f4c80
2 files changed