libtuning: Implement a minimal yaml parser

At the moment this just reads the yaml file and returns it verbatim.
This needs to evolve further in the near future.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

utils/tuning/config-example.yaml

@@ -0,0 +1,12 @@
+general:
+  disable: []
+  plot: []
+  alsc:
+    do_alsc_colour: 1
+    luminance_strength: 0.5
+  awb:
+    greyworld: 0
+  macbeth:
+    small: 1
+    show: 0
+#  blacklevel: 32

utils/tuning/libtuning/parsers/yaml_parser.py

@@ -5,13 +5,16 @@
 # Parser for YAML format config file
 
 from .parser import Parser
+import yaml
 
 
 class YamlParser(Parser):
     def __init__(self):
         super().__init__()
 
-    # \todo Implement this (it's fine for now as we don't need a config for
-    # rkisp1 LSC, which is the only user of this so far)
     def parse(self, config_file: str, modules: list) -> (dict, list):
-        return {}, []
+        # Dummy implementation that just reads the file
+        with open(config_file, 'r') as f:
+            config = yaml.safe_load(f)
+
+        return config, []