add hostname option in dhcp discover

    Hostname option has been removed from dhcp discover since IDFv3.2.
But it remains in dhcp request due to which ESP32 can not get IPv4 address
from some APs. Re-add hostname option to dhcp discover to solve this issue.

diff --git a/components/lwip/lwip b/components/lwip/lwip
index 046fadde072b5fca94bea84c16cce5ecbfd6948e..0865edf80ad0a96e0eaf2bbedbad350cab248115 160000 (submodule)
--- a/components/lwip/lwip
+++ b/components/lwip/lwip
@@ -1 +1 @@
-Subproject commit 046fadde072b5fca94bea84c16cce5ecbfd6948e
+Subproject commit 0865edf80ad0a96e0eaf2bbedbad350cab248115