Allowing zeroes in trusted OS SMC return values

Trusted OSes should preserve or fill by zeroes the values of x1-x3
registers across an SMC call in order to prevent data leakage. The
behaviour of OP-TEE regarding to this has changed recently from
preserving values to filling them by zeroes. This patch utilitizes the
newly added allow_zeros[] parameter of the smc_check_match function to
make the tests compatible with OP-TEE commit 6e558fa94ab0 or later.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I52ddfb69261833a3fba76c5f89d27d1ea13043b0