uboot-imx

tqma6_wru4: Fix the reset delay for the the LAN8720 PHY

According to the LAN8720 datasheet tpurstd (time that reset line should
stay asserted) is 25ms.

So do as suggested by the LAN8720 datasheet.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>