The sleep_clk frequency isn't exactly 32000 and is instead either
32764.5 or 32768 depending on the board configuration. But other clock
devices expect a generic, rounded rate of 32000. Exceeding this rate
will cause errors enabling and setting rate of these clocks. So change
the frequency to 32000 since having a precise frequency here isn't
important.
Change-Id: Ic65a962677cf430fc2fca1126c0b1d84636debfb