meson, configure: move --tls-priority to meson

Use the new support for string option parsing.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/meson.build b/meson.build
index 6606c97..ae3b3a4 100644
--- a/meson.build
+++ b/meson.build
@@ -1598,6 +1598,7 @@
   config_host_data.set('CONFIG_TRACE_' + k.to_upper(), true)
 endforeach
 config_host_data.set_quoted('CONFIG_TRACE_FILE', get_option('trace_file'))
+config_host_data.set_quoted('CONFIG_TLS_PRIORITY', get_option('tls_priority'))
 if iasl.found()
   config_host_data.set_quoted('CONFIG_IASL', iasl.full_path())
 endif
@@ -3820,7 +3821,7 @@
 
 # Crypto
 summary_info = {}
-summary_info += {'TLS priority':      config_host['CONFIG_TLS_PRIORITY']}
+summary_info += {'TLS priority':      get_option('tls_priority')}
 summary_info += {'GNUTLS support':    gnutls}
 if gnutls.found()
   summary_info += {'  GNUTLS crypto':   gnutls_crypto.found()}