examples: re-enable SystemView examples for esp32s2

Closes IDF-1357

examples/system/sysview_tracing/CMakeLists.txt

@@ -2,6 +2,5 @@
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.5)
 
-set(SUPPORTED_TARGETS esp32)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(sysview_tracing)

examples/system/sysview_tracing/README.md

@@ -119,11 +119,15 @@ NOTE: In order to run this example you need OpenOCD version `v0.10.0-esp32-20181
 
     Using this file GDB will connect to the target, reset it, and start tracing when it hit breakpoint at `app_main`. Trace data will be saved to `/tmp/sysview_example.svdat`.
 
+    **Note:** if running the example on ESP32-S2, modify the command name in gdbinit file from `esp32 sysview` to `esp32_s2 sysview`.
+
 6.  Run GDB using the following command from the project root directory:
 
     ```
     xtensa-esp32-elf-gdb -x gdbinit build/sysview_tracing.elf
-    ``` 
+    ```
+
+    **Note:** Replace `xtensa-esp32-elf-gdb` with `xtensa-esp32s2-elf-gdb` if running the example on ESP32-S2.
 
 7.  When program prints the last message, interrupt its execution (e.g. by pressing `CTRL+C`) and type the following command in GDB console to stop tracing:
 

examples/system/sysview_tracing_heap_log/CMakeLists.txt

@@ -2,6 +2,5 @@
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.5)
 
-set(SUPPORTED_TARGETS esp32)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(sysview_tracing_heap_log)

examples/system/sysview_tracing_heap_log/README.md

@@ -40,6 +40,9 @@ To run the example and collect trace data:
     ```
     xtensa-esp32-elf-gdb -x gdbinit build/sysview_tracing_heap_log.elf
     ```
+
+    **Note**: if running the example on ESP32-S2, modify the command name in gdbinit file from `esp32 sysview` to `esp32_s2 sysview`, and run `xtensa-esp32s2-elf-gdb` instead of `xtensa-esp32-elf-gdb`.
+
 2. When program stops at `heap_trace_stop`  quit GDB.
 
 3. Open trace data file in SystemView tool.