meson: fix gpiod dependency

gpiod is not a "common" dependency, but only needed for specific
options.  Add it as a dependency only when necessary.

Name the dependency as `libgpiod_dep` to follow meson conventions.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ib650f5fe4e7085733f43eba608502e7e21a5c8db
diff --git a/bios/meson.build b/bios/meson.build
index 5515e2a..48136d6 100644
--- a/bios/meson.build
+++ b/bios/meson.build
@@ -14,7 +14,7 @@
         phosphor_logging_dep,
         pdi_dep,
         boost_dep,
-        libgpiod,
+        libgpiod_dep,
         libpldm_dep,
     ],
     link_with: [libpldmutil, software_common_lib],