ARM: dts: Fix the RPM clock controller compatible string

The right string is msm8660 and there is also apq8060, but not
apq8660, so fix this.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>