Extend CPPCHECK scope to kernel tests

Remove the broad kernels/test CPPCHECK exclusion and keep the remaining
suppressions scoped to that tree.

Kernel tests use fixture helpers, generated-style test data, and GTest
macros that cppcheck cannot consistently resolve as direct use sites.
Suppress those test-harness findings locally while keeping the rest of
the CPPCHECK configuration active for kernels/test.

Signed-off-by: Per Held <per.held@arm.com>
Change-Id: I033afb7b59b961a99d6716ff3faa068a0eed2f6a

Author: perheld

.lintrunner.toml

@@ -195,7 +195,6 @@ exclude_patterns = [
     # Kernel areas to onboard separately.
     'kernels/optimized/**',
     'kernels/portable/**',
-    'kernels/test/**',
 
     # Runtime areas to onboard incrementally.
     'runtime/backend/**',
@@ -234,6 +233,16 @@ command = [
     '--extra-arg=--suppress=unusedFunction:*kernels/quantized/*',
     '--extra-arg=--suppress=constParameterReference:*kernels/quantized/*',
     '--extra-arg=--suppress=suspiciousFloatingPointCast:*kernels/quantized/*',
+    # Kernel tests use fixture helpers, generated-style test cases, and GTest
+    # macros that cppcheck cannot consistently resolve as direct use sites.
+    '--extra-arg=--suppress=unusedFunction:*kernels/test/*',
+    '--extra-arg=--suppress=unreadVariable:*kernels/test/*',
+    '--extra-arg=--suppress=unknownMacro:*kernels/test/*',
+    '--extra-arg=--suppress=syntaxError:*kernels/test/*',
+    '--extra-arg=--suppress=passedByValue:*kernels/test/*',
+    '--extra-arg=--suppress=duplicateBranch:*kernels/test/*',
+    '--extra-arg=--suppress=useStlAlgorithm:*kernels/test/*',
+    '--extra-arg=--suppress=functionStatic:*kernels/test/*',
     '--',
     '@{{PATHSFILE}}'
 ]