samples: multicore: empty: Update documentation and add other builds

The documentation has been updated to reference other supported
processors and sample file has been updated to test on these
platforms

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

doc/nrf/includes/sample_board_rows.txt

@@ -214,6 +214,10 @@
 
 | :ref:`nRF54H20 DK <ug_nrf54h20_gs>` | PCA10175 | :zephyr:board:`nrf54h20dk <nrf54h20dk>` | ``nrf54h20dk/nrf54h20/cpuppr`` |
 
+.. nrf54h20dk_nrf54h20_cpuflpr
+
+| :ref:`nRF54H20 DK <ug_nrf54h20_gs>` | PCA10175 | :zephyr:board:`nrf54h20dk <nrf54h20dk>` | ``nrf54h20dk/nrf54h20/cpuflpr`` |
+
 .. native_posix
 
 | Native Posix | | native_posix | ``native_posix`` |

samples/basic/empty/README.rst

@@ -9,7 +9,17 @@ Empty firmware for multiple core SoCs
 
 The sample demonstrates how to generate an empty network (or other) core firmware.
 The sample is used only by the applications that do not use the other core(s).
-In the mentioned case, the empty network core sample is automatically added to build by the :kconfig:option:`SB_CONFIG_NETCORE_EMPTY` sysbuild Kconfig option.
+An empty image can be added to a project using the following options (depending upon if an SoC has the CPU):
+
++----------------------------------------------+--------------------------------------------+
+| Core                                         | Sysbuild Kconfig                           |
++==============================================+============================================+
+| Network/radio processor                      | :kconfig:option:`SB_CONFIG_NETCORE_EMPTY`  |
++----------------------------------------------+--------------------------------------------+
+| Fast Lightweight peripheral processor (FLPR) | :kconfig:option:`SB_CONFIG_FLPRCORE_EMPTY` |
++----------------------------------------------+--------------------------------------------+
+| Peripheral processor (PPR)                   | :kconfig:option:`SB_CONFIG_PPRCORE_EMPTY`  |
++----------------------------------------------+--------------------------------------------+
 
 Requirements
 ************

samples/basic/empty/sample.yaml

@@ -8,9 +8,15 @@ tests:
     integration_platforms:
       - nrf5340dk/nrf5340/cpunet
       - thingy53/nrf5340/cpunet
+      - nrf54l15dk/nrf54l15/cpuflpr
+      - nrf54h20dk/nrf54h20/cpuflpr
+      - nrf54h20dk/nrf54h20/cpuppr
     platform_allow:
       - nrf5340dk/nrf5340/cpunet
       - thingy53/nrf5340/cpunet
+      - nrf54l15dk/nrf54l15/cpuflpr
+      - nrf54h20dk/nrf54h20/cpuflpr
+      - nrf54h20dk/nrf54h20/cpuppr
     tags:
       - ci_build
       - sysbuild