dev-libs/wlroots: minor fixes

dev-libs/wlroots: minor fixes

 - Update copyright header in all versions;

 - Use ${PN} wherever possible;

 - Remove explicit dependency on meson (no longer required);

 - Fix the order of (R)DEPEND;

 - wayland-protocols is a build-time dependency: move it in BDEPEND;

 - Add xcb-util-image dependency (required);

 - Remove `xkb` flag from libxcb dep (not required for >=wlroots-0.2).

Package-Manager: Portage-2.3.59, Repoman-2.3.12
Signed-off-by: Niccolò Scatena <speedjack95@gmail.com>
Closes: https://github.com/gentoo/gentoo/pull/11017
Signed-off-by: Aaron Bauman <bman@gentoo.org>