faraday: remove orphaned header file

Commit 11232139 ("nds32: Remove the architecture") removed the nds32
architecture, and with it the last user of the Faraday AHB controller
header file.

Consequently remove that header file as well.

This was found because the inclusion guard was misspelled.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>