sysbuild: kconfig: Add hide options Kconfig

Adds a Kconfig that, when enabled, will hide the Kconfig tree of NCS
for sysbuild

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

Author: nordicjm

sysbuild/Kconfig.sysbuild

@@ -6,6 +6,13 @@
 
 # This file contains extra images which can be used with sysbuild based builds.
 
+config NRF_CONNECT_SDK_HIDE_OPTIONS
+	bool
+	help
+	  If enabled, will hide NCS Kconfig options from being visible in the Kconfig tree.
+
+if !NRF_CONNECT_SDK_HIDE_OPTIONS
+
 menuconfig PARTITION_MANAGER
 	bool "Partition Manager"
 	default y if SOC_FAMILY_NORDIC_NRF
@@ -87,3 +94,5 @@ rsource "Kconfig.lwm2m_carrier"
 rsource "Kconfig.cracen"
 rsource "Kconfig.tfm"
 rsource "Kconfig.periphconf"
+
+endif # !NRF_CONNECT_SDK_HIDE_OPTIONS