audio: Make pcspk card selectable again

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Since we moved pcspk into hwlib, CONFIG_PCSPK is no longer defined per
target. Therefore, statically built soundhw array in arch_init.c stopped
including this card.

Work around this by re-adding this define to config-target.mak.
Long-term, a dynamic creation of this soundhw list will be necessary.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: malc <av1474@comtv.ru>

configure

@@ -3881,6 +3881,11 @@ if test "$target_bsd_user" = "yes" ; then
   echo "CONFIG_BSD_USER=y" >> $config_target_mak
 fi
 
+# the static way of configuring available audio cards requires this workaround
+if test "$target_user_only" != "yes" && grep -q CONFIG_PCSPK $source_path/default-configs/$target.mak; then
+  echo "CONFIG_PCSPK=y" >> $config_target_mak
+fi
+
 # generate QEMU_CFLAGS/LDFLAGS for targets
 
 cflags=""