build: remove the AUDIO_SUPPORT and DISPLAY_SUPPORT symbols

Nothing tests either symbol any more. AUDIO_SUPPORT was also selected by
PCI_SUPPORT and USB_SUPPORT, which stood for "a sound card could be
plugged in here": audio hardware sits behind MMC, SPI, a Bluetooth UART
or an SoC PCM block just as often, so the inference never held. The
display feature was derived from a literal CONFIG_VGA_CONSOLE or CONFIG_FB
in a kernel fragment, which misses every target whose fbdev came from DRM
emulation.

Delete both symbols, the two selects, the feature translations and the
derivation.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

scripts/target-metadata.pl

@@ -10,11 +10,9 @@ sub target_config_features(@) {
 
 	while ($_ = shift @_) {
 		/^arm_v(\w+)$/ and $ret .= "\tselect arm_v$1\n";
-		/^audio$/ and $ret .= "\tselect AUDIO_SUPPORT\n";
 		/^boot-part$/ and $ret .= "\tselect USES_BOOT_PART\n";
 		/^broken$/ and $ret .= "\tdepends on BROKEN\n";
 		/^cpiogz$/ and $ret .= "\tselect USES_CPIOGZ\n";
-		/^display$/ and $ret .= "\tselect DISPLAY_SUPPORT\n";
 		/^dt$/ and $ret .= "\tselect USES_DEVICETREE\n";
 		/^dt-overlay$/ and $ret .= "\tselect HAS_DT_OVERLAY_SUPPORT\n";
 		/^emmc$/ and $ret .= "\tselect EMMC_SUPPORT\n";