phy/micrel: Rename KS80xx to KSZ80xx

There is no such part as KS8001, KS8041 or KS8051. There are only
KSZ8001, KSZ8041 and KSZ8051. Rename these parts as such to match
the Micrel naming.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David J. Choi <david.choi@micrel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Cc: Linux ARM kernel <linux-arm-kernel@lists.infradead.org>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>