boot: zephyr: Update changed Nordic family Kconfig

Updates a Kconfig that was renamed

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>
diff --git a/boot/zephyr/Kconfig.serial_recovery b/boot/zephyr/Kconfig.serial_recovery
index 74bced7..fe82697 100644
--- a/boot/zephyr/Kconfig.serial_recovery
+++ b/boot/zephyr/Kconfig.serial_recovery
@@ -98,7 +98,7 @@
 
 config BOOT_ERASE_PROGRESSIVELY
 	bool "Erase flash progressively when receiving new firmware"
-	default y if SOC_FAMILY_NRF
+	default y if SOC_FAMILY_NORDIC_NRF
 	help
 	 If enabled, flash is erased as necessary when receiving new firmware,
 	 instead of erasing the whole image slot at once. This is necessary