soc/arm/silabs_ex32/efr32bg27: select `CONFIG_SOC_GECKO_SE`

This commits selects the `CONFIG_SOC_GECKO_SE` option for the BG27 SoC
series. This is required for BLE support, as it enables the inclusion of
the `sl_protocol_crypto` component from SiLabs HAL.

Signed-off-by: Filip Kokosinski <fkokosinski@antmicro.com>
diff --git a/soc/arm/silabs_exx32/efr32bg27/Kconfig.series b/soc/arm/silabs_exx32/efr32bg27/Kconfig.series
index e8680b4..6118e18 100644
--- a/soc/arm/silabs_exx32/efr32bg27/Kconfig.series
+++ b/soc/arm/silabs_exx32/efr32bg27/Kconfig.series
@@ -19,5 +19,6 @@
 	select SOC_GECKO_CMU
 	select SOC_GECKO_CORE
 	select SOC_GECKO_DEV_INIT
+	select SOC_GECKO_SE
 	help
 	  Enable support for EFR32BG27 Blue Gecko MCU series