add cmake for pi zero (renamed from pi zero_w), build but the flash size seem wrong (only 24 bytes for text)

examples/build_system/cmake/cpu/arm1176jzf-s.cmake

@@ -0,0 +1,19 @@
+if (TOOLCHAIN STREQUAL "gcc")
+  set(TOOLCHAIN_COMMON_FLAGS
+    -mcpu=arm1176jzf-s
+  )
+  # set(FREERTOS_PORT GCC_ARM_CM0 CACHE INTERNAL "")
+
+elseif (TOOLCHAIN STREQUAL "clang")
+  set(TOOLCHAIN_COMMON_FLAGS
+    --target=arm-none-eabi
+    -mcpu=arm1176jzf-s
+    -mfpu=none
+    -mfloat-abi=soft
+  )
+  #set(FREERTOS_PORT GCC_ARM_CM0 CACHE INTERNAL "")
+
+elseif (TOOLCHAIN STREQUAL "iar")
+  message(FATAL_ERROR "IAR not supported")
+
+endif ()