eal: deprecate log functions

eal: deprecate log functions

Deprecate the following functions:
- rte_set_log_level(), replaced by rte_log_set_global_level()
- rte_get_log_level(), replaced by rte_log_get_global_level()
- rte_set_log_type(), replaced by rte_log_set_level()
- rte_get_log_type(), replaced by rte_log_get_level()

The new functions provide a better control of the per-type log level,
and have a better name prefix (rte_log_).

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>