arm: socfpga: reset: Add EMAC reset functions

arm: socfpga: reset: Add EMAC reset functions

Add functions to reset the EMAC ethernet blocks. We cannot handle
two EMAC ethernet blocks yet, therefore the ifdefs. Once there is
hardware using both EMAC blocks, this ifdef will have to go.

Signed-off-by: Marek Vasut <[email protected]>
Cc: Chin Liang See <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Albert Aribaud <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Wolfgang Denk <[email protected]>
Cc: Pavel Machek <[email protected]>
Acked-by: Pavel Machek <[email protected]>