fix default value for serial recovery mode detect port for nRFx devices .

Zephyr's SOC_FAMILY_NRF5 keyword was changed to SOC_FAMILY_NRF to
align with zephyr code-base.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/zephyr/Kconfig b/boot/zephyr/Kconfig
index 840de9a..6883a2f 100644
--- a/boot/zephyr/Kconfig
+++ b/boot/zephyr/Kconfig
@@ -54,7 +54,7 @@
 config BOOT_SERIAL_DETECT_PORT
 	string
 	prompt "GPIO Port to trigger serial recovery mode"
-	default GPIO_0 if SOC_FAMILY_NRF5
+	default GPIO_0 if SOC_FAMILY_NRF
 	depends on MCUBOOT_SERIAL
 	help
 	  Serial recovery detect port