[P200][Cisco]Fix P200 SerDes six-tap programming

P200 uses FIR fields for the primary tap settings. Route P200 through the FIR configuration path and program post2/post3 when six-tap programming is enabled.

Author: kyliechen-cisco

fboss/agent/hw/sai/switch/npu/SaiPortManager.cpp

@@ -1759,7 +1759,9 @@ SaiPortManager::serdesAttributesFromSwPinConfigs(
       if (platform_->getAsic()->getAsicType() ==
               cfg::AsicType::ASIC_TYPE_YUBA ||
           platform_->getAsic()->getAsicType() ==
-              cfg::AsicType::ASIC_TYPE_G202X) {
+              cfg::AsicType::ASIC_TYPE_G202X ||
+          platform_->getAsic()->getAsicType() ==
+              cfg::AsicType::ASIC_TYPE_P200) {
         if (auto firPre1 = tx->firPre1()) {
           txPre1.push_back(zeroPreemphasis ? 0 : *firPre1);
         }
@@ -1775,6 +1777,14 @@ SaiPortManager::serdesAttributesFromSwPinConfigs(
         if (auto firPost1 = tx->firPost1()) {
           txPost1.push_back(zeroPreemphasis ? 0 : *firPost1);
         }
+        if (platform_->getAsic()->getAsicType() ==
+                cfg::AsicType::ASIC_TYPE_P200 &&
+            FLAGS_sai_configure_six_tap &&
+            platform_->getAsic()->isSupported(
+                HwAsic::Feature::SAI_CONFIGURE_SIX_TAP)) {
+          txPost2.push_back(zeroPreemphasis ? 0 : *tx->post2());
+          txPost3.push_back(zeroPreemphasis ? 0 : *tx->post3());
+        }
         if (auto diffEncoderEn = tx->diffEncoderEn()) {
           txDiffEncoderEn.push_back(diffEncoderEn.value());
         }