alpha_pll_check_rate_margin
ret = alpha_pll_check_rate_margin(hw, rrate, rate);
ret = alpha_pll_check_rate_margin(hw, rrate, cal_freq);
ret = alpha_pll_check_rate_margin(hw, rrate, rate);
ret = alpha_pll_check_rate_margin(hw, rrate, rate);
ret = alpha_pll_check_rate_margin(hw, rrate, rate);