Revert "Documentation: net: add flow control guide and document ethtool API"

This reverts commit 7bd80ed.

I should not have merged it to begin with due to pending review and
changes to be addressed.

Link: https://patch.msgid.link/c6f3af12df9b7998920a02027fc8893ce82afc4c.1759239721.git.pabeni@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Paolo Abeni

Documentation/netlink/specs/ethtool.yaml

@@ -864,9 +864,7 @@ attribute-sets:
 
   -
     name: pause-stat
-    doc: Statistics counters for link-wide PAUSE frames (IEEE 802.3 Annex 31B).
     attr-cnt-name: __ethtool-a-pause-stat-cnt
-    enum-name: ethtool-a-pause-stat
     attributes:
       -
         name: unspec
@@ -877,17 +875,13 @@ attribute-sets:
         type: pad
       -
         name: tx-frames
-        doc: Number of PAUSE frames transmitted.
         type: u64
       -
         name: rx-frames
-        doc: Number of PAUSE frames received.
         type: u64
   -
     name: pause
-    doc: Parameters for link-wide PAUSE (IEEE 802.3 Annex 31B).
     attr-cnt-name: __ethtool-a-pause-cnt
-    enum-name: ethtool-a-pause
     attributes:
       -
         name: unspec
@@ -899,40 +893,19 @@ attribute-sets:
         nested-attributes: header
       -
         name: autoneg
-        doc: |
-          Acts as a mode selector for the driver.
-          On GET: indicates the driver's behavior. If true, the driver will
-          respect the negotiated outcome; if false, the driver will use a
-          forced configuration.
-          On SET: if true, the driver configures the PHY's advertisement based
-          on the rx and tx attributes. If false, the driver forces the MAC
-          into the state defined by the rx and tx attributes.
         type: u8
       -
         name: rx
-        doc: |
-          Enable receiving PAUSE frames (pausing local TX).
-          On GET: reflects the currently preferred configuration state.
         type: u8
       -
         name: tx
-        doc: |
-          Enable transmitting PAUSE frames (pausing peer TX).
-          On GET: reflects the currently preferred configuration state.
         type: u8
       -
         name: stats
-        doc: |
-          Contains the pause statistics counters. The source of these
-          statistics is determined by stats-src.
         type: nest
         nested-attributes: pause-stat
       -
         name: stats-src
-        doc: |
-          Selects the source of the MAC statistics, values from
-          enum ethtool_mac_stats_src. This allows requesting statistics
-          from the individual components of the MAC Merge layer.
         type: u32
   -
     name: eee