qemu: correct installation dir for firmware's json

Close: void-linux#23495

srcpkgs/qemu/template

@@ -1,7 +1,7 @@
 # Template file for 'qemu'
 pkgname=qemu
 version=5.0.0
-revision=2
+revision=3
 short_desc="Open Source Processor Emulator"
 maintainer="Helmut Pozimski <helmut@pozimski.eu>"
 license="GPL-2.0-or-later, LGPL-2.1-or-later"
@@ -81,6 +81,15 @@ do_install() {
 	make DESTDIR=${DESTDIR} install
 	# qemu-bridge-helper must be setuid for non privileged users.
 	chmod u+s ${DESTDIR}/usr/libexec/qemu-bridge-helper
+	# The firmware JSON files should be searched for in three directories
+	# * /usr/share/qemu/firmware
+	# * /etc/qemu/firmware
+	# * $XDG_CONFIG_HOME/qemu/firmware
+	# See: https://git.qemu.org/?p=qemu.git;a=blob;f=docs/interop/firmware.json;h=240f565397ae0e754e85976f2d4b5e3873ae8211;hb=HEAD#l311
+	vmkdir usr/share/qemu
+	mv ${DESTDIR}/usr/lib/qemu/firmware ${DESTDIR}/usr/share/qemu/
+	# This shouldn't be necessary, just in case.
+	ln -sf ../../share/qemu/firmware ${DESTDIR}/usr/lib/qemu/
 
 	vsv qemu-ga
 }