uboot-imx

MX28: Fixup the ad-hoc use of DIGCTL_MICROSECONDS

Use proper struct-based access for this register in the SPL code.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>