net/ena/base: improve style and comments

net/ena/base: improve style and comments

List of changes:
  * Comment style was adjusted for the functions
  * The keys_num at "struct ena_admin_feature_rss_flow_hash_control" was
    renamed to the key_parts to better describe it's meaning
  * The RSS indirection table was called "REDIRECTION" -> changed to
    INDIRECTION
  * Change AENQ field "syndrom" -> "syndrome"
  * Calculate number of the RSS key parts or whole key by using the
    common way: sizeof of the first element of the RSS key
  * Add description of the "enum ena_admin_aq_feature_id"
  * Rename "map_rx_buf_bidirectional" field as "rx_buf_mirroring"
  * Other minor style fixes (remove extra spaces, add missing line break,
    improve indentation)
  * Remove unused macros ENA_ADMIN_EXTRA_PROPERTIES_*
  * Restructure the "if {} else if {} else" conditional statement for
    setting up the meta descriptor

Fixes: 99ecfbf845b3 ("ena: import communication layer")
Fixes: b68309be44c0 ("net/ena/base: update communication layer for the ENAv2")
Fixes: b2b02edeb0d6 ("net/ena/base: upgrade HAL for new HW features")
Cc: stable@dpdk.org
Signed-off-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>