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: Ib0b26af4bd0e8685c83b1b0181f70bfca59ab2bc
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/dbus-sdr/meson.build b/dbus-sdr/meson.build
index 37b5669..a937485 100644
--- a/dbus-sdr/meson.build
+++ b/dbus-sdr/meson.build
@@ -9,7 +9,7 @@
 
 hybrid_src = []
 
-if not get_option('hybrid-sensors').disabled()
+if get_option('hybrid-sensors').allowed()
     hybrid_src = [
         'sensorhandler.cpp',
         'sensordatahandler.cpp',
@@ -19,7 +19,7 @@
 endif
 
 sensorsoem_src = []
-if not get_option('sensors-oem').disabled()
+if get_option('sensors-oem').allowed()
     sensorsoem_src = ['dbus-sdr/sensorcommands_oem.cpp']
 endif