uboot-imx

armv8: configs: ls1012a: correct the generic timer frequency

On ls1012a soc, core clock source frequency is fixed at 100Mhz.
Generic timer frequency is core clock source divided by 4, which
is 25Mhz.

Signed-off-by: Tang Yuantian <andy.tang@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>