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: Iea489ded084f43d245e7b17f210e83bc2398dd6d
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/subprojects/dhcp-done/meson.build b/subprojects/dhcp-done/meson.build
index 0bc7198..cfb6b76 100644
--- a/subprojects/dhcp-done/meson.build
+++ b/subprojects/dhcp-done/meson.build
@@ -69,6 +69,6 @@
 
 build_tests = get_option('tests')
 
-#if not build_tests.disabled()
+#if build_tests.allowed()
 subdir('test')
 #endif
diff --git a/subprojects/metrics-ipmi-blobs/meson.build b/subprojects/metrics-ipmi-blobs/meson.build
index 15eead9..331ad86 100644
--- a/subprojects/metrics-ipmi-blobs/meson.build
+++ b/subprojects/metrics-ipmi-blobs/meson.build
@@ -106,6 +106,6 @@
   install: true,
   install_dir: get_option('libdir') / 'blob-ipmid')
 
-if not get_option('tests').disabled()
+if get_option('tests').allowed()
   subdir('test')
 endif
diff --git a/subprojects/ncsid/meson.build b/subprojects/ncsid/meson.build
index 5d0db18..41563fc 100644
--- a/subprojects/ncsid/meson.build
+++ b/subprojects/ncsid/meson.build
@@ -29,6 +29,6 @@
 
 build_tests = get_option('tests')
 
-if not build_tests.disabled()
+if build_tests.allowed()
   subdir('test')
 endif