[PATCH] bsp/tms570: fix get time resolution after infrastructure change to timecounter.

[Martin Galvan]

Hello Premysl! Thanks for this patch.

Could you tell us why is this patch needed, and where does the new
formula come from? From what I saw, HALCoGen generates a macro called
RTI_FREQ which has the value from the previous version of the formula
(i.e. if BSP_PLL_OUT_CLOCK == 180 MHz, RTI_FREQ == 90).

I also looked at the TMS570 Technical Reference Manual entry on CPUC0,
but it doesn't mention that formula.

It would also be nice if you mentioned which setup did you test this
on (i.e. loading RTEMS from RAM or flash).