tools: binman: ti_board_cfg: Check for linting problems

Use yamllint for checking whether YAML configuration files are adhering
to default yamllint rules.

Signed-off-by: Neha Malcom Francis <n-francis@ti.com>
Suggested-by: Nishanth Menon <nm@ti.com>
diff --git a/tools/buildman/requirements.txt b/tools/buildman/requirements.txt
index a1efcb9..4a31e69 100644
--- a/tools/buildman/requirements.txt
+++ b/tools/buildman/requirements.txt
@@ -1,2 +1,3 @@
 jsonschema==4.17.3
 pyyaml==6.0
+yamllint==1.26.3