configs: Add all groups configuration JSON through meson.build

Map all directories and JSON files under the configs folder to
/usr/share/phosphor-led-manager.

Currently, the configs file only contains `rainier-2u` and
`rainier-4u` group configuration JSON files.

Tested: Switch to `meson` to compile ledManager and saw that
        rainier-2u and rainier-4u files are mapped to
        `/usr/share/phosphor-led-manager`.

~# ls /usr/share/phosphor-led-manager/ibm,rainier-2u
   led-group-config.json

~# ls /usr/share/phosphor-led-manager/ibm,rainier-4u
   led-group-config.json

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I35e86a911da7bf58825c70ce1e650c3bf0aba126
diff --git a/meson.build b/meson.build
index 7f01052..874a498 100644
--- a/meson.build
+++ b/meson.build
@@ -158,3 +158,7 @@
 if not build_tests.disabled()
   subdir('test')
 endif
+
+install_subdir('configs',
+    install_dir: get_option('datadir') / 'phosphor-led-manager',
+    strip_directory: true)