clk: ingenic: Fix round_rate misbehaving with non-integer dividers

clk: ingenic: Fix round_rate misbehaving with non-integer dividers

Take a parent rate of 180 MHz, and a requested rate of 4.285715 MHz.
This results in a theorical divider of 41.999993 which is then rounded
up to 42. The .round_rate function would then return (180 MHz / 42) as
the clock, rounded down, so 4.285714 MHz.

Calling clk_set_rate on 4.285714 MHz would round the rate again, and
give a theorical divider of 42,0000028, now rounded up to 43, and the
rate returned would be (180 MHz / 43) which is 4.186046 MHz, aka. not
what we requested.

Fix this by rounding up the divisions.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Maarten ter Huurne <maarten@treewalker.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>