ci: add more ppc ci

Author: inkydragon

.github/workflows/cross.yml

@@ -20,6 +20,8 @@ jobs:
           # TODO: fix arm cross build
           # - { arch: arm,      triple: arm-linux-gnueabi }
           - { arch: aarch64,  triple: aarch64-linux-gnu }
+          - { arch: ppc,      triple: powerpc-linux-gnu }
+          - { arch: ppc64,    triple: powerpc64-linux-gnu }
           - { arch: ppc64le,  triple: powerpc64le-linux-gnu }
           - { arch: mips,     triple: mips-linux-gnu }
           - { arch: mipsel,   triple: mipsel-linux-gnu }