drm/amd/display: Move link functions from dc to dc_link

	link_bw_kbps *= 8;   /* 8 bits per byte*/

	link_bw_kbps *= link_setting->lane_count;

#ifdef CONFIG_DRM_AMD_DC_DSC_SUPPORT

	if (link->dpcd_caps.fec_cap.bits.FEC_CAPABLE) {

		/* Account for FEC overhead.

		 * We have to do it based on caps,

		 * and not based on FEC being set ready,

		 * because FEC is set ready too late in

		 * the process to correctly be picked up

		 * by mode enumeration.

		 *

		 * There's enough zeros at the end of 'kbps'

		 * that make the below operation 100% precise

		 * for our purposes.

		 * 'long long' makes it work even for HDMI 2.1

		 * max bandwidth (and much, much bigger bandwidths

		 * than that, actually).

		 *

		 * NOTE: Reducing link BW by 3% may not be precise

		 * because it may be a stream BT that increases by 3%, and so

		 * 1/1.03 = 0.970873 factor should have been used instead,

		 * but the difference is minimal and is in a safe direction,

		 * which all works well around potential ambiguity of DP 1.4a spec.

		 */

		long long fec_link_bw_kbps = link_bw_kbps * 970LL;

		link_bw_kbps = (uint32_t)(fec_link_bw_kbps / 1000LL);

	}

#endif

	return link_bw_kbps;

}