net: add fastboot TCP support

Known limitations are
1. fastboot reboot doesn't work (answering OK but not rebooting)
2. flashing isn't supported (TCP transport only limitation)

The command syntax is
fastboot tcp

Signed-off-by: Dmitrii Merkurev <dimorinny@google.com>
Cc: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
Cc: Simon Glass <sjg@chromium.org>
Сс: Joe Hershberger <joe.hershberger@ni.com>
Сс: Ramon Fried <rfried.dev@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index e9ed6ac..c8f72e9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -988,10 +988,12 @@
 F:	doc/android/fastboot*.rst
 F:	include/fastboot.h
 F:	include/fastboot-internal.h
-F:	include/net/fastboot.h
+F:	include/net/fastboot_tcp.h
+F:	include/net/fastboot_udp.h
 F:	drivers/fastboot/
 F:	drivers/usb/gadget/f_fastboot.c
-F:	net/fastboot.c
+F:	net/fastboot_tcp.c
+F:	net/fastboot_udp.c
 F:	test/dm/fastboot.c
 
 FPGA