Add additional checks to detect more PowerPC architecture name variants

Author: erikbs

CMakeLists.txt

@@ -60,6 +60,8 @@ elseif(_bits EQUAL 32)
     set(_default_arch arm)
   elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^mips")
     set(_default_arch mips32)
+  elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(powerpc|ppc32)")
+    set(_default_arch ppc32)
   else()
     set(_default_arch i386)
   endif()
@@ -69,6 +71,8 @@ else()
     set(_default_arch arm64)
   elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^mips")
     set(_default_arch mips64)
+  elseif(CMAKE_SYSTEM_PROCESSOR MATCHES "^(powerpc|ppc64)")
+    set(_default_arch ppc64)
   else()
     set(_default_arch x86_64)
   endif()