Simplify sysctl.c code to only the used CPU freqency function.
This reduces the size of the final firmware by 4KB.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
The math.h is not required anymore and it also gives
compile error for certain toolchains hence thsi patch
removes math.h include from kendryte/k210/sysctl.c.
Signed-off-by: Anup Patel <anup.patel@wdc.com>