net/: Augment CONFIG_COMMANDS tests with defined(CONFIG_CMD_*).

This is a compatibility step that allows both the older form
and the new form to co-exist for a while until the older can
be removed entirely.

All transformations are of the form:
Before:
    #if (CONFIG_COMMANDS & CFG_CMD_AUTOSCRIPT)
After:
    #if (CONFIG_COMMANDS & CFG_CMD_AUTOSCRIPT) || defined(CONFIG_CMD_AUTOSCRIPT)

Signed-off-by: Jon Loeliger <jdl@freescale.com>