docs: networking: device_drivers: replace some characters

The conversion tools used during DocBook/LaTeX/html/Markdown->ReST
conversion and some cut-and-pasted text contain some characters that
aren't easily reachable on standard keyboards and/or could cause
troubles when parsed by the documentation build system.

Replace the occurences of the following characters:

- U+00a0 (' '): NO-BREAK SPACE
as it can cause lines being truncated on PDF output

Reviewed-by: Jesse Brandeburg <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Link: https://lore.kernel.org/r/9bd9f5[e-mail]
Signed-off-by: Jonathan Corbet <[e-mail]>

Documentation/networking/device_drivers/ethernet/intel/i40e.rst

···
 "ethtool -T <netdev name>" to get a definitive list of PTP capabilities
 supported by the device.
 
-IEEE 802.1ad (QinQ) Support
+IEEE 802.1ad (QinQ) Support
 ---------------------------
 The IEEE 802.1ad standard, informally known as QinQ, allows for multiple VLAN
 IDs within a single Ethernet frame. VLAN IDs are sometimes referred to as
···
 Maximum Bandwidth is not restricted, because no more than 100% of a port's
 bandwidth can ever be used.
 
-NOTE: X710/XXV710 devices fail to enable Max VFs (64) when Multiple Functions
-per Port (MFP) and SR-IOV are enabled. An error from i40e is logged that says
+NOTE: X710/XXV710 devices fail to enable Max VFs (64) when Multiple Functions
+per Port (MFP) and SR-IOV are enabled. An error from i40e is logged that says
 "add vsi failed for VF N, aq_err 16". To workaround the issue, enable less than
 64 virtual functions (VFs).
 

Documentation/networking/device_drivers/ethernet/intel/iavf.rst

···
 - AVF device ID
 - HW mailbox is used for VF to PF communications (including on Windows)
 
-IEEE 802.1ad (QinQ) Support
+IEEE 802.1ad (QinQ) Support
 ---------------------------
 The IEEE 802.1ad standard, informally known as QinQ, allows for multiple VLAN
 IDs within a single Ethernet frame. VLAN IDs are sometimes referred to as