meson: add support for loongson's mips/mips64 arch.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6836>
diff --git a/meson.build b/meson.build
index 3b7e115..50e105e 100644
--- a/meson.build
+++ b/meson.build
@@ -162,6 +162,8 @@
       dri_drivers = ['i915', 'i965', 'r100', 'r200', 'nouveau']
     elif ['arm', 'aarch64'].contains(host_machine.cpu_family())
       dri_drivers = []
+    elif ['mips', 'mips64'].contains(host_machine.cpu_family())
+      dri_drivers = ['r100', 'r200', 'nouveau']
     else
       error('Unknown architecture @0@. Please pass -Ddri-drivers to set driver options. Patches gladly accepted to fix this.'.format(
             host_machine.cpu_family()))
@@ -198,6 +200,10 @@
         'kmsro', 'v3d', 'vc4', 'freedreno', 'etnaviv', 'nouveau',
         'tegra', 'virgl', 'lima', 'panfrost', 'swrast'
       ]
+    elif ['mips', 'mips64'].contains(host_machine.cpu_family())
+      gallium_drivers = [
+        'r300', 'r600', 'radeonsi', 'nouveau', 'virgl', 'swrast'
+      ]
     else
       error('Unknown architecture @0@. Please pass -Dgallium-drivers to set driver options. Patches gladly accepted to fix this.'.format(
             host_machine.cpu_family()))
@@ -246,6 +252,8 @@
       _vulkan_drivers = ['amd', 'intel', 'swrast']
     elif ['arm', 'aarch64'].contains(host_machine.cpu_family())
       _vulkan_drivers = ['swrast']
+    elif ['mips', 'mips64'].contains(host_machine.cpu_family())
+      _vulkan_drivers = ['amd', 'swrast']
     else
       error('Unknown architecture @0@. Please pass -Dvulkan-drivers to set driver options. Patches gladly accepted to fix this.'.format(
             host_machine.cpu_family()))