CPU (Linux): fix CPU detection on some PPC platforms (#1640)

On some PowerPC devices (notably the Nintendo Wii and Nintendo Wii U),
fastfetch detects the CPU incorrectly.  It goes down the code path
of 'detectSocName()', and actually matches the model of the device
itself... as the CPU model name.  This is obviously incorrect, and
leads to reporting such as 'CPU: wii'.  Disable this code path
alltogether on PPC to prevent this, and just let it pull from cpuinfo.
This lets it have correct CPU reporting, such as on the Wii, giving
'CPU: 750CL @ 0.73GHz'.

src/detection/cpu/cpu_linux.c

@@ -608,7 +608,7 @@ FF_MAYBE_UNUSED static const char* detectCPUOthers(const FFCPUOptions* options,
 
     #if __ANDROID__
     detectAndroid(cpu);
-    #else
+    #elif !__powerpc__ && !__powerpc
     detectSocName(cpu);
     #endif