drm/amd/display: dce_link_encoder: add DCE6 specific macros,functions

[Why]
DCE6 has no DP_DPHY_SCRAM_CNTL register

[How]
Add DCE6 specific macros definitions for LE registers
DCE6 LE macros will avoid buiding errors when using DCE6 headers
Add dce60_set_dp_phy_pattern_hbr2_compliance_cp2520_2() w/o Scramble Control programming
Add dce60_set_dp_phy_pattern_passthrough_mode() w/o Scramble Control programming
Add dce60_configure_encoder() w/o Scramble Control programming
Add dce60_link_encoder_enable_dp_output() w/ dce60_configure_encoder
Add dce60_link_encoder_enable_dp_mst_output() w/ dce60_configure_encoder
Add dce60_link_encoder_dp_set_phy_pattern() w/ dce60_set_dp_phy_pattern_passthrough_mode
Use dce60_link_encoder_enable_dp_output() in dce60_lnk_enc_funcs
Use dce60_link_encoder_enable_dp_mst_output() in dce60_lnk_enc_funcs
Use dce60_link_encoder_dp_set_phy_pattern() in dce60_lnk_enc_funcs
Add DCE6 specific dce60_link_encoder_construct

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Mauro Rossi <issor.oruam@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>