隐式转换警告优化

[Cherish-Gww]

https://github.com/hpmicro/hpm_sdk/blob/276af9395fde9ca963ac5bf7ad1e516163168bfa/drivers/src/hpm_enc_pos_drv.c#L52C1-L53C1

当打开-Werror=double-promotion编译参数时，该出会出现float to double的隐式转换。

建议修改为：

uint32_t encoder_rad_to_position(float rad)
{
    double tmp = (double)rad;
    const double _2pi = 6.283185307179586;

    while (tmp < 0) {
        tmp += _2pi;
    }
    while (tmp > _2pi) {
        tmp -= _2pi;
    }

    return (uint32_t)((tmp / _2pi) * (double)0xFFFFFFFF);
}

[chenzhihong007]

好的，谢谢提醒，将在下一个release修复。