net: fastboot: make UDP port net: configurable

The fastboot protocol uses per default the UDP port 5554. In some cases
it might be needed to change the used port. The fastboot utility provides
a way to specifiy an other port number to use already.

  fastboot -s udp:192.168.1.76:1234 boot fastboot.img

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/drivers/fastboot/Kconfig b/drivers/fastboot/Kconfig
index d5e4a02..b97c67b 100644
--- a/drivers/fastboot/Kconfig
+++ b/drivers/fastboot/Kconfig
@@ -21,6 +21,13 @@
 	help
 	  This enables the fastboot protocol over UDP.
 
+config UDP_FUNCTION_FASTBOOT_PORT
+	depends on UDP_FUNCTION_FASTBOOT
+	int "Define FASTBOOT UDP port"
+	default 5554
+	help
+	  The fastboot protocol requires a UDP port number.
+
 if FASTBOOT
 
 config FASTBOOT_BUF_ADDR