OMAP2xxx clock: GFX functional clock rates are not independently changeable

According to the OMAP242x TRM Rev X Figure 5-15 "Clock Output Control
- Functional Clocks 2", the GFX functional clocks should be marked
both DELAYED_APP and CONFIG_PARTICIPANT, meaning that their rates must
be reprogrammed as part of a larger OPP set change.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Richard Woodruff <r-woodruff2@ti.com>