ARM: LPC32xx: clock.c: Fix lpc-eth clock reference

During a complex merge for v3.4, one line of the commit
c20b909b

 ("ARM: LPC32xx: Ethernet support") was
reverted wrongly ("lpc-eth.0" -> "lpc-net.0") while the other conflicts were
merged correctly. This patch re-applies the clock name "lpc-eth.0".

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Olof Johansson <olof@lixom.net>