net: Switch to common values for SOCK_STREAM, SOCK_DGRAM

Many OSes use values SOCK_STREAM = 1, SOCK_DGRAM = 2, apparently
inherited from the original BSD Unix, which introduced Sockets API.
These values are exposed as numbers in many places, e.g. with a
debugger, when printing just as numbers, etc., so use the above
common values to avoid possible confusion.

Jira: ZEP-2066

Change-Id: I0477abc79e2b43ef83f9fb11a66092f2b41f75fa
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>