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

Summary:

Every time we clone/set up ExecuTorch, we're downloading cadence dependencies.

Let's make this an on-demand step. Otherwise, this is downloading almost 1GB of code.

Author: mergennachin

.gitmodules

@@ -55,18 +55,12 @@
 [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

@@ -0,0 +1,2 @@
+hifi/third-party/nnlib/nnlib-hifi4
+fusion_g3/third-party/nnlib/nnlib-FusionG3

backends/cadence/build_cadence_fusionG3.sh

@@ -12,6 +12,7 @@ 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_hifi4.sh

@@ -12,6 +12,7 @@ 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

backends/cadence/fusion_g3/third-party/nnlib/nnlib-FusionG3

@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+
+SCRIPT_DIR_PATH="$(
+    cd -- "$(dirname "$0")" >/dev/null 2>&1
+    pwd -P
+)"
+
+red=`tput setaf 1`
+green=`tput setaf 2`
+
+EXECUTORCH_ROOT_PATH=$(realpath "$SCRIPT_DIR_PATH/../../")
+CADENCE_DIR_PATH="$EXECUTORCH_ROOT_PATH/backends/cadence"
+HIFI_DIR_PATH="$CADENCE_DIR_PATH/hifi/third-party/nnlib/nnlib-hifi4"
+FUSION_DIR_PATH="$CADENCE_DIR_PATH/fusion_g3/third-party/nnlib/nnlib-FusionG3"
+
+cd "$EXECUTORCH_ROOT_PATH"
+
+## HiFi 
+
+rm -rf "$HIFI_DIR_PATH"
+mkdir -p "$HIFI_DIR_PATH"
+
+echo "${green}ExecuTorch: Cloning hifi nnlib"
+git clone "https://github.com/foss-xtensa/nnlib-hifi4.git" $HIFI_DIR_PATH
+cd $HIFI_DIR_PATH
+STATUS=$?
+if [ $STATUS -ne 0 ]; then
+    echo "${red}ExecuTorch: Failed to clone hifi nnlib."
+    exit 1
+fi
+
+git checkout 102944a6f76a0de4d81adc431f3f132f517aa87f
+
+
+## Fusion G3
+
+rm -rf "$FUSION_DIR_PATH"
+mkdir -p "$FUSION_DIR_PATH"
+
+echo "${green}ExecuTorch: Cloning fusion g3"
+git clone "https://github.com/foss-xtensa/nnlib-FusionG3.git" $FUSION_DIR_PATH
+cd $FUSION_DIR_PATH
+STATUS=$?
+if [ $STATUS -ne 0 ]; then
+    echo "${red}ExecuTorch: Failed to clone fusion g3."
+    exit 1
+fi
+
+git checkout 11230f47b587b074ba0881deb28beb85db566ac2