omap3:clock: configure GFX clock to 200MHz for AM/DM37x

omap3:clock: configure GFX clock to 200MHz for AM/DM37x

AM/DM37x is another OMAP3 variant, where the GFX clock has been
boosted to 192MHz/200MHz. So fix the GFX_DIV value for this change.

HW Errata: Due to dependency of TV out clock of 54MHz, it is not
possible to configure GFX to 192MHz. So as per HW errats, the
recommended GFX clock is 200MHz (=CORE_CLK/2).

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>