LAVA: Decouple LAVA monitors among reg tests

As the control on BL2, S/NS regression tests has been decoupled during
build stage, the one in LAVA monitor should also decoupled.

This patch groups monitors for regression tests based on the setting of
"TEST_REGRESSION". Also also update the code format to make it easy to
read.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I508675c7acc54dc81078f255b4d40b6773150926
2 files changed