weston: Cleanup and fix x11 and xwayland dependencies

For the x11 backend package config, drop the redundant dependencies
libxcb and cairo. The former is listed twice in the package config,
while the latter is also listed globally.

For the xwayland package config, add the missing dependencies libxcb
and libxcursor. These dependencies are hidden when the x11 backend is
enabled by default. When the default setting is overridden to disable
the x11 backend, the following error occurs:
```
| Run-time dependency xcursor found: NO (tried pkgconfig and cmake)
|
| ../git/xwayland/meson.build:34:2: ERROR: Problem encountered: xwayland requires xcursor which was not found. Or, you can use '-Dxwayland=false'.
```

(From OE-Core rev: 49f4dd391b408a850d13010c90492c621b7912c3)

Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-graphics/wayland/weston_11.0.1.bb

@@ -57,7 +57,7 @@ PACKAGECONFIG[kms] = "-Dbackend-drm=true,-Dbackend-drm=false,drm udev virtual/eg
 # Weston on Wayland (nested Weston)
 PACKAGECONFIG[wayland] = "-Dbackend-wayland=true,-Dbackend-wayland=false,virtual/egl virtual/libgles2"
 # Weston on X11
-PACKAGECONFIG[x11] = "-Dbackend-x11=true,-Dbackend-x11=false,virtual/libx11 libxcb libxcb libxcursor cairo"
+PACKAGECONFIG[x11] = "-Dbackend-x11=true,-Dbackend-x11=false,virtual/libx11 libxcb libxcursor"
 # Headless Weston
 PACKAGECONFIG[headless] = "-Dbackend-headless=true,-Dbackend-headless=false"
 # Weston on RDP
@@ -73,7 +73,7 @@ PACKAGECONFIG[webp] = "-Dimage-webp=true,-Dimage-webp=false,libwebp"
 # Weston with systemd-login support
 PACKAGECONFIG[systemd] = "-Dsystemd=true -Dlauncher-logind=true,-Dsystemd=false -Dlauncher-logind=false,systemd dbus"
 # Weston with Xwayland support (requires X11 and Wayland)
-PACKAGECONFIG[xwayland] = "-Dxwayland=true,-Dxwayland=false,xwayland"
+PACKAGECONFIG[xwayland] = "-Dxwayland=true,-Dxwayland=false,libxcb libxcursor xwayland"
 # colord CMS support
 PACKAGECONFIG[colord] = "-Ddeprecated-color-management-colord=true,-Ddeprecated-color-management-colord=false,colord"
 # Clients support