Revert "Remove cadence submodule from top-level dependencies (#7839)"

This reverts commit 2411c99.

Author: huydhn

.gitmodules

@@ -55,12 +55,18 @@
 [submodule "third-party/ios-cmake"]
 	path = third-party/ios-cmake
 	url = https://github.com/leetal/ios-cmake
+[submodule "backends/cadence/hifi/third-party/nnlib/nnlib-hifi4"]
+	path = backends/cadence/hifi/third-party/nnlib/nnlib-hifi4
+	url = https://github.com/foss-xtensa/nnlib-hifi4.git
 [submodule "third-party/prelude"]
 	path = third-party/prelude
 	url = https://github.com/facebook/buck2-prelude.git
 [submodule "third-party/pybind11"]
 	path = third-party/pybind11
 	url = https://github.com/pybind/pybind11.git
+[submodule "backends/cadence/fusion_g3/third-party/nnlib/nnlib-FusionG3"]
+	path = backends/cadence/fusion_g3/third-party/nnlib/nnlib-FusionG3
+	url = https://github.com/foss-xtensa/nnlib-FusionG3.git
 [submodule "third-party/ao"]
 	path = third-party/ao
 	url = https://github.com/pytorch/ao.git

backends/cadence/.gitignore

@@ -12,7 +12,6 @@ unset XTENSA_CORE
 export XTENSA_CORE=FCV_FG3GP
 git submodule sync
 git submodule update --init
-./backends/cadence/install_requirements.sh
 ./install_executorch.sh
 
 rm -rf cmake-out

backends/cadence/build_cadence_fusionG3.sh

@@ -12,7 +12,6 @@ unset XTENSA_CORE
 export XTENSA_CORE=nxp_rt600_RI23_11_newlib
 git submodule sync
 git submodule update --init
-./backends/cadence/install_requirements.sh
 ./install_executorch.sh
 
 rm -rf cmake-out