OMAPDSS: DPI: Fix wrong pixel clock limit

DPI is supposed to skip odd dividers in the clock path when the pixel
clock is higher than 100MHz. The code, however, defines the pixel clock
limit as 1MHz. This causes the driver to skip valid clock dividers,
possibly making the pixel clock to be further away from the requested
one than necessary.

Fix the clock limit to 100MHz.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: NeilBrown <neilb@suse.de>