sys-apps/razergenie: Inherit xdg-utils, add xdg_icon_cache_update

Closes: https://bugs.gentoo.org/966339
Signed-off-by: Mike Pagano <mpagano@gentoo.org>

sys-apps/razergenie/razergenie-1.3.0.ebuild

@@ -2,7 +2,7 @@
 # Distributed under the terms of the GNU General Public License v2
 EAPI=8
 
-inherit meson
+inherit meson xdg-utils
 
 MY_P="RazerGenie-${PV}"
 DESCRIPTION="Razer devices configurator"
@@ -31,3 +31,11 @@ BDEPEND="
 src_configure() {
 	meson_src_configure
 }
+
+pkg_postinst() {
+	xdg_icon_cache_update
+}
+
+pkg_postrm() {
+	xdg_icon_cache_update
+}