[PATCH i-g-t] tests/kms_display_modes: Skip mirrored pipe combinations

[Jeevan B <jeevan.b@intel.com>]

Use a canonical pipe ordering in extended-mode-basic so each pipe pair
is tested only once. This removes mirrored combinations (A-B and B-A)
that provide duplicate coverage.

Reducing these redundant combinations lowers the total number of dynamic
subtests, helping prevent incomplete test execution in CI while
preserving coverage of all pipe and output pairings.

Signed-off-by: Jeevan B <jeevan.b@intel.com>
---
 tests/kms_display_modes.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/kms_display_modes.c b/tests/kms_display_modes.c
index d8aae4256..983733b9b 100644
--- a/tests/kms_display_modes.c
+++ b/tests/kms_display_modes.c
@@ -190,6 +190,9 @@ static void run_extendedmode_test(data_t *data) {
 			if (crtc1 == crtc2)
 				continue;
 
+			if (crtc1->pipe > crtc2->pipe)
+				continue;
+
 			if (output1 == output2)
 				continue;
 
-- 
2.43.0