meson: add necessary subprojects

Add subprojects for all the direct dependencies of the project such
that the project can be built outside of a Yocto SDK on a typical
Linux development system.

  - Update the .gitignore to ignore the subproject source directories.
  - Update the .gitignore to ignore alternative build subdirectory
    names as is typical with most projects in the openbmc organization.
  - Add wrap files for direct dependencies, copied from other
    repositories that already have the same dependencies.
  - Modify the meson.build dependency for libgpiod so that the C++
    bindings are included.
  - Add many missing dependencies throughout.
  - Sort all dependencies alphabetically for consistency.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I0feb6f0f175e6dba0b00a2c2b666eb0801575734
diff --git a/subprojects/libgpiod.wrap b/subprojects/libgpiod.wrap
new file mode 100644
index 0000000..f650e74
--- /dev/null
+++ b/subprojects/libgpiod.wrap
@@ -0,0 +1,13 @@
+[wrap-file]
+directory = libgpiod-1.6.3
+source_url = https://git.kernel.org/pub/scm/libs/libgpiod/libgpiod.git/snapshot/libgpiod-1.6.3.tar.gz
+source_filename = libgpiod-1.6.3.tar.gz
+source_hash = eb446070be1444fd7d32d32bbca53c2f3bbb0a21193db86198cf6050b7a28441
+patch_filename = libgpiod_1.6.3-1_patch.zip
+patch_url = https://wrapdb.mesonbuild.com/v2/libgpiod_1.6.3-1/get_patch
+patch_hash = 76821c637073679a88f77593c6f7ce65b4b5abf8c998f823fffa13918c8761df
+
+[provide]
+libgpiod = gpiod_dep
+libgpiodcxx = gpiodcxx_dep
+