build: use allowed over enabled or not-disabled

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`.
Switch all uses of `not disabled` to `allowed`.

Change-Id: If5d6047137a085eaa6a3de0580aff96488596825
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/test/meson.build b/test/meson.build
index 0def0f8..802dbe3 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -30,7 +30,7 @@
 endif
 
 parser_build_arguments = []
-if get_option('ipz_ecc_check').enabled()
+if get_option('ipz_ecc_check').allowed()
     parser_build_arguments += ['-DIPZ_ECC_CHECK']
 endif