net: stmmac: dwmac4: Fix high address display by updating reg_space[] from register values

The high address will display as 0 if the driver does not set the
reg_space[]. To fix this, read the high address registers and
update the reg_space[] accordingly.

Fixes: fbf68229 ("net: stmmac: unify registers dumps methods")
Signed-off-by: Ley Foon Tan <leyfoon.tan@starfivetech.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241021054625.1791965-1-leyfoon.tan@starfivetech.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>