Patch a9e93e8 has erroneously removed some comments which are
important to understand why the bus frequency is multiplied by
two during the spi transfer.

Reword the previous comment to a more appropriate message.
Suggested-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NAndi Shyti <andi.shyti@samsung.com>
Reviewed-by: NMichael Turquette <mturquette@baylibre.com>
Signed-off-by: NMark Brown <broonie@kernel.org>