configure: fix --audio-drv-list help message

--audio-drv-list is now establishing which audio drivers to try if -audiodev
is not used; drivers for -audiodev are configured with --enable/--disable
options or possibly --without-default-features.  Adjust the help message
for --audio-drv-list.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/configure b/configure
index 4c444e1..97fee36 100755
--- a/configure
+++ b/configure
@@ -1390,7 +1390,7 @@
   --disable-strip          disable stripping binaries
   --disable-werror         disable compilation abort on warning
   --disable-stack-protector disable compiler-provided stack protection
-  --audio-drv-list=LIST    set audio drivers list
+  --audio-drv-list=LIST    set audio drivers to try if -audiodev is not used
   --block-drv-whitelist=L  Same as --block-drv-rw-whitelist=L
   --block-drv-rw-whitelist=L
                            set block driver read-write whitelist