zephyr/Kconfig: reference missing new Nordic boards keywords

Updated boards reference names.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
diff --git a/boot/zephyr/Kconfig b/boot/zephyr/Kconfig
index 4f1b172..b196952 100644
--- a/boot/zephyr/Kconfig
+++ b/boot/zephyr/Kconfig
@@ -313,8 +313,8 @@
 
 choice
 	prompt "Serial device"
-	default BOOT_SERIAL_UART if !BOARD_NRF52840_PCA10059
-	default BOOT_SERIAL_CDC_ACM if BOARD_NRF52840_PCA10059
+	default BOOT_SERIAL_UART if !BOARD_NRF52840DONGLE_NRF52840
+	default BOOT_SERIAL_CDC_ACM if BOARD_NRF52840DONGLE_NRF52840
 
 config BOOT_SERIAL_UART
 	bool "UART"
@@ -343,9 +343,9 @@
 
 config BOOT_SERIAL_DETECT_PIN
 	int "Pin to trigger serial recovery mode"
-	default 6 if BOARD_NRF9160_PCA10090
+	default 6 if BOARD_NRF9160DK_NRF9160
 	default 11 if BOARD_NRF52840DK_NRF52840
-	default 13 if BOARD_NRF52_PCA10040
+	default 13 if BOARD_NRF52DK_NRF52832
 	default 23 if BOARD_NRF5340_DK_NRF5340_CPUAPP || BOARD_NRF5340_DK_NRF5340_CPUAPPNS
 	help
 	  Pin on the serial detect port which triggers serial recovery mode.