mimix1050rt: ethernet initialization corrected

Fixes board PHY initialization.
ENET_RST and ENET_INT pins are also used as USER_LED/JTAG_TDI and
INT1_COMBO/JTAG_TDO. Initialization needs to set these pins to power and
interrupt for the PHY Transciver. PHY reset works without busy waiting.
Moved pin initialization back to PRE_KERNEL_1 to fix UART bug and busy
wait not required.

Signed-off-by: Andrei Gansari <andrei.gansari@nxp.com>