tests: remove FVP_Foundation model support

This model has been subsumed by the FVP_Base model, which is now
available publicly. We no longer have a need to test the Foundation
model, and can shave off a few minutes of CI time by removing it.

Signed-off-by: Chris Kay <chris.kay@arm.com>
Change-Id: Iac6160cebe20aec5be89d9ae15c0f4b72dca655e
44 files changed