tests: intel_s1000: i2c: Support green and white LED blinking

S1000 i2c test was blinking only blue and red lights. However, if
we have to distinguish between 2 test images for whatever reasons,
it is handy to have one test image blinking blue-red while the
other blinks green-white.

Signed-off-by: Rajavardhan Gundi <rajavardhan.gundi@intel.com>