posix: create a typedef for in_addr_t

A recent change made it so that in_addr_t was no longer defined.

Define in_addr_t in arpa/inet.h

Signed-off-by: Chris Friedt <chrisfriedt@gmail.com>

Author: cfriedt

include/zephyr/posix/arpa/inet.h

@@ -32,6 +32,8 @@ static inline int inet_pton(sa_family_t family, const char *src, void *dst)
 
 #endif /* CONFIG_NET_SOCKETS_POSIX_NAMES */
 
+typedef uint32_t in_addr_t;
+
 in_addr_t inet_addr(const char *cp);
 char *inet_ntoa(struct in_addr in);