net: bcmasp: Restore programming of TX map vector register

net: bcmasp: Restore programming of TX map vector register

On ASP versions v2.x we need to program the TX map vector register to
properly exercise end-to-end flow control, otherwise the TX engine can
either lock-up, or cause the hardware calculated checksum to be
wrong/corrupted when multiple back to back packets are being submitted
for transmission. This register defaults to 0, which means no flow
control being applied.

Fixes: e9f31435ee7d ("net: bcmasp: Add support for asp-v3.0")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20250718212242.3447751-1-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>