macb: remove conditional clk handling

AT91 now provides both "pclk" and "hclk" aliases for the the macb
device so we can use the same clk handling paths for both AT91 and
AVR32.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>