net: ethernet: stmicro: stmmac: move queue reset to dedicated functions

Move queue reset to dedicated functions. This aside from a simple
cleanup is also required to allocate a dma conf without resetting the tx
queue while the device is temporarily detached as now the reset is not
part of the dma init function and can be done later in the code flow.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>