build: use allowed over enabled

Meson feature options are typically in a tri-state of enabled, disabled,
or auto.  The enabled and disabled functions on an option (from
`get_option`) no longer return true for auto features.  Instead, the
expectation is to use `allowed()` which is true for both enabled and auto.

Switch all uses of `enabled` to `allowed`.

Change-Id: I0db07582db115b8f7511183e37a718dad23f04ca
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/meson.build b/meson.build
index d4b8fe7..4e84478 100644
--- a/meson.build
+++ b/meson.build
@@ -12,7 +12,7 @@
   ]
 )
 
-if (get_option('raw-peci').enabled())
+if (get_option('raw-peci').allowed())
   sdbusplus = dependency('sdbusplus')
 
   systemd = dependency('systemd', required: true)
@@ -92,7 +92,7 @@
   install_dir: bindir
 )
 
-if (get_option('raw-peci').enabled())
+if (get_option('raw-peci').allowed())
   executable(
     'raw-peci',
     'dbus_raw_peci.cpp',