[nrf fromtree] soc: Add SOC_COMPATIBLE_NRF54LM20* options

In preparation for simulated nRF54LM20 targets, let's add kconfig
options aking to the ones we have for the nRF54L15 devices.

Signed-off-by: Alberto Escolar Piedras <[email protected]>
(cherry picked from commit 65fb246)

Author: aescolar

soc/Kconfig

@@ -49,6 +49,12 @@ config SOC_COMPATIBLE_NRF54L15
 config SOC_COMPATIBLE_NRF54L15_CPUAPP
 	bool
 
+config SOC_COMPATIBLE_NRF54LM20A
+	bool
+
+config SOC_COMPATIBLE_NRF54LM20A_CPUAPP
+	bool
+
 config SOC_DEPRECATED_RELEASE
 	string
 	help