fix: paths for spmc fvp run job

Fix location where FVP is downloaded to.
Fix PATH to prebuilt clang toolchain when building Hafnium.
Only run kokoro/test_spmc.sh script (Hypervisor+SPMC configuration).
The Hypervisor only FVP suite (kokoro/test.sh --fvp) is not yet stable
enough to be automated.

Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
Change-Id: I82f57541c429344c289abc0ceebd447a1b6c6692
1 file changed