drivers/video/fbdev/omap/lcd_mipid.c: Use time comparison kernel macros

Use time_before_eq time comparison defind kernel macro
that has safety check.

Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>