net: pch_gbe: Remove get_bus_info HAL abstraction

For some reason the pch_gbe driver contains a struct pch_gbe_functions
with pointers used by a HAL abstraction layer, even though there is only
one implementation of each function.

This patch removes the get_bus_info abstraction. Its single
implementation (pch_gbe_plat_get_bus_info) only sets values within a
struct pch_gbe_bus_info which is never used, so we simply remove the
call to it in pch_gbe_probe & remove struct pch_gbe_bus_info entirely.

Now that struct pch_gbe_functions is empty we remove it entirely too.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Signed-off-by: David S. Miller <davem@davemloft.net>