Be more forgiving of early OMAP3 revisions
Early OMAP3 chip revisions have very tight porch & sync limits. This means that many standard VESA/CEA aren't supported (e.g. VGA 60), along with 90% of the kernel's builtin modes. With Kernel 6.32 this will typically result in the OS failing to find a valid screen mode at boot, likely resulting in the system failing to boot completely.
Fix this by (on old chips only) allowing some fudging of the mode timings, by shrinking the sync width and increasing the porch width to ensure the overall timing is maintained. This is roughly equivalent to what would have happened with earlier kernel versions, which didn't always vet modes before applying them.
Tested on rev C2 BeagleBoard (OMAP3530 ES 3.0; porch+sync limits are larger in ES 3.1)