drm/nouveau/mcp89/mmu: Use mcp77_mmu_new instead of g84_mmu_new on MCP89.

Fix a crash or broken depth testing in all OpenGL applications that use the
depth buffer on MCP89 (GeForce 320M) seen on a MacBook Pro Late 2010.

The bug is tracked in https://bugs.freedesktop.org/show_bug.cgi?id=108500

Signed-off-by: Timo Wiren <timo.wiren@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nvkm/engine/device/base.c

@@ -1316,7 +1316,7 @@ nvaf_chipset = {
 	.i2c = g94_i2c_new,
 	.imem = nv50_instmem_new,
 	.mc = gt215_mc_new,
-	.mmu = g84_mmu_new,
+	.mmu = mcp77_mmu_new,
 	.mxm = nv50_mxm_new,
 	.pci = g94_pci_new,
 	.pmu = gt215_pmu_new,