net: spacemit: Remove unused buff_addr fields
These were never used. Just remove them.
No functional change intended.
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
Link: https://patch.msgid.link/20260305-k1-ethernet-cleanup-buff_addr-v1-1-e978ef119231@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
authored by