ath79: ubnt-bullet-m-xw: Remove pll-data property from eth0 node

ath79: ubnt-bullet-m-xw: Remove pll-data property from eth0 node

It's not necessary as it's already defined in ar934x.dtsi to:

  pll-data = <0x16000000 0x00000101 0x00001616>;

And in ar71xx it's currently set to the same values:

 #define AR934X_PLL_VAL_1000	0x16000000
 #define AR934X_PLL_VAL_100	0x00000101
 #define AR934X_PLL_VAL_10	0x00001616

And dumping the value from the airOS v6.1.7 has the same value:

  AR934X_PLL_ETH_XMII_CONTROL_REG 0x1805002C 0x101

Signed-off-by: Petr Štetiar <ynezz@true.cz>