There is a little bit of floating point code in cy_sysclk.c. For now
add compile protection for this code using CONFIG_FLOAT. This code
utilizes some libm functions like ceil(). So if / when the functions
Cy_SysClk_EcoConfigure & Cy_SysClk_FllConfigure are needed we'll also
new to probably pull in newlib.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>