Fix builds on s390x (#402)

Fixes #401

Author: jonathanspw

src/fastfetch.c

@@ -879,6 +879,8 @@ static void parseOption(FFinstance* instance, FFdata* data, const char* key, con
             #define FF_ARCHITECTURE "powerpc"
         #elif defined(__riscv__) || defined(__riscv)
             #define FF_ARCHITECTURE "riscv"
+        #elif defined(__s390x__)
+            #define FF_ARCHITECTURE "s390x"
         #elif
             #define FF_ARCHITECTURE "unknown"
         #endif