[doc] Remove unused link from IP Checklist template

Removed unused links `D?_REVIEWED` from the IP checklist template file.

Signed-off-by: Eunchan Kim <eunchan@google.com>
diff --git a/doc/project/ip_checklist.md.tpl b/doc/project/ip_checklist.md.tpl
index a8cdfd7..139dedd 100644
--- a/doc/project/ip_checklist.md.tpl
+++ b/doc/project/ip_checklist.md.tpl
@@ -33,7 +33,6 @@
 [FUNC_IMPLEMENTED]:   {{<relref "/doc/project/checklist.md#func-implemented" >}}
 [ASSERT_KNOWN_ADDED]: {{<relref "/doc/project/checklist.md#assert-known-added" >}}
 [LINT_SETUP]:         {{<relref "/doc/project/checklist.md#lint-setup" >}}
-[D1_REVIEWED]:        {{<relref "/doc/project/checklist.md#d1-reviewed" >}}
 
 ### D2
 
@@ -74,7 +73,6 @@
 [CDC_SETUP]:           {{<relref "/doc/project/checklist.md#cdc-setup" >}}
 [CDC_SYNCMACRO]:       {{<relref "/doc/project/checklist.md#cdc-syncmacro" >}}
 [FPGA_TIMING]:         {{<relref "/doc/project/checklist.md#fpga-timing" >}}
-[D2_REVIEWED]:         {{<relref "/doc/project/checklist.md#d2-reviewed" >}}
 
 ### D3
 
@@ -104,7 +102,6 @@
 [REVIEW_SW_FATAL_ERR]:  {{<relref "/doc/project/checklist.md#review-sw-fatal-err" >}}
 [REVIEW_SW_CHANGE]:     {{<relref "/doc/project/checklist.md#review-sw-change" >}}
 [REVIEW_SW_ERRATA]:     {{<relref "/doc/project/checklist.md#review-sw-errata" >}}
-[D3_REVIEWED]:          {{<relref "/doc/project/checklist.md#d3-reviewed" >}}
 
 ## Verification Checklist