meson/megadriver: simplify setting common megadriver arguments

Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32333>

bin/meson.build

@@ -11,3 +11,6 @@ gen_vs_module_defs_normal_command = [
 ]
 symbols_check = find_program('symbols-check.py')
 install_megadrivers_py = find_program('install_megadrivers.py')
+install_megadrivers = [
+  install_megadrivers_py.full_path(),
+]

src/gallium/targets/dri/meson.build

@@ -90,7 +90,7 @@ if with_gallium_va or with_gallium_vdpau
 
   if va_drivers.length() > 0
     meson.add_install_script(
-      install_megadrivers_py.full_path(),
+      install_megadrivers,
       libgallium_dri.full_path(),
       va_drivers_path,
       va_drivers,
@@ -101,7 +101,7 @@ if with_gallium_va or with_gallium_vdpau
 
   if vdpau_drivers.length() > 0
     meson.add_install_script(
-      install_megadrivers_py.full_path(),
+      install_megadrivers,
       libgallium_dri.full_path(),
       vdpau_drivers_path,
       vdpau_drivers,

src/gallium/targets/dril/meson.build

@@ -143,7 +143,7 @@ endif
 
 if dril_drivers.length() > 0
   meson.add_install_script(
-    install_megadrivers_py.full_path(),
+    install_megadrivers,
     dril_dri.full_path(),
     dri_drivers_path,
     dril_drivers,

src/gallium/targets/va/meson.build

@@ -99,7 +99,7 @@ else
 
   if va_drivers.length() > 0
     meson.add_install_script(
-      install_megadrivers_py.full_path(),
+      install_megadrivers,
       libva_gallium.full_path(),
       va_drivers_path,
       va_drivers,

src/gallium/targets/vdpau/meson.build

@@ -61,7 +61,7 @@ endforeach
 
 if vdpau_drivers.length() > 0
   meson.add_install_script(
-    install_megadrivers_py.full_path(),
+    install_megadrivers,
     libvdpau_gallium.full_path(),
     vdpau_drivers_path,
     vdpau_drivers,