triagebot: Add autolabels for PowerPC

(backport <#4523>)
(cherry picked from commit 9ccce07)

Author: tgross35

triagebot.toml

@@ -87,6 +87,24 @@ trigger_files = ["src/unix/linux_like/linux/musl"]
 [autolabel."O-newlib"]
 trigger_files = ["src/unix/newlib"]
 
+[autolabel."O-powerpc"]
+trigger_files = [
+    "src/unix/aix/powerpc64.rs",
+    "src/unix/bsd/freebsdlike/freebsd/powerpc.rs",
+    "src/unix/bsd/freebsdlike/freebsd/powerpc64.rs",
+    "src/unix/bsd/netbsdlike/netbsd/powerpc.rs",
+    "src/unix/bsd/netbsdlike/openbsd/powerpc.rs",
+    "src/unix/bsd/netbsdlike/openbsd/powerpc64.rs",
+    "src/unix/linux_like/linux/arch/powerpc/",
+    "src/unix/linux_like/linux/gnu/b32/powerpc.rs",
+    "src/unix/linux_like/linux/gnu/b64/powerpc64/",
+    "src/unix/linux_like/linux/musl/b32/powerpc.rs",
+    "src/unix/linux_like/linux/musl/b64/powerpc64.rs",
+    "src/unix/newlib/powerpc/",
+    "src/vxworks/powerpc.rs",
+    "src/vxworks/powerpc64.rs",
+]
+
 [autolabel."O-redox"]
 trigger_files = ["src/unix/redox"]