Test: Add attestation claim value check switch

Control checking for hard-coded claim values in the attestation suite
by introducing the 'ATTEST_CLAIM_VALUE_CHECK' flag. When set to 'ON',
the test will check if the claim values match the constant values found
in 'platform/ext/common/template/attest_hal.c'.

Signed-off-by: Balint Matyi <Balint.Matyi@arm.com>
Change-Id: I22ab1471609d6b931deaf97f31cb3a0dcd83fda0