net: stmmac: Rework and fix TX Timeout code

Currently TX Timeout handler does not behaves as expected and leads to
an unrecoverable state. Rework current implementation of TX Timeout
handling to actually perform a complete reset of the driver state and IP.

We use deferred work to init a task which will be responsible for
resetting the system.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>