spi/davinci: Fix clock prescale factor computation

Computation of the clock prescaler value returned bogus results if
the requested SPI clock was impossible to set. It now sets either
the maximum or minimum clock frequency, as appropriate.

Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
1 file changed