Platform: Enable IRQ testing on some platforms by default

This patch enables the following IRQ tests by default so that
CI could cover the testing:
 - FLIH test on AN521
 - SLIH test on Musca-B1

Because FLIH and SLIH test can not be enabled at the same time,
let users choose which to enable on other platforms.

Note: Currently, FLIH test is only supported on AN519 and AN521.

Change-Id: I2c40b46841ac54a3c8bc5e788c9184047626db4a
Signed-off-by: Kevin Peng <kevin.peng@arm.com>
2 files changed