Update submodules and gitmodules configuration

.gitmodules

@@ -87,22 +87,22 @@
 	url = https://github.com/ucb-bar/libgloss-htif.git
 [submodule "toolchains/riscv-tools/riscv-isa-sim"]
 	path = toolchains/riscv-tools/riscv-isa-sim
-	url = https://github.com/richardyrh/riscv-isa-sim
+	url = https://gh-proxy.org/https://github.com/richardyrh/riscv-isa-sim
 [submodule "toolchains/riscv-tools/riscv-openocd"]
 	path = toolchains/riscv-tools/riscv-openocd
-	url = https://github.com/riscv/riscv-openocd.git
+	url = https://gh-proxy.org/https://github.com/riscv/riscv-openocd.git
 [submodule "toolchains/riscv-tools/riscv-pk"]
 	path = toolchains/riscv-tools/riscv-pk
-	url = https://github.com/riscv-software-src/riscv-pk.git
+	url = https://gh-proxy.org/https://github.com/riscv-software-src/riscv-pk.git
 [submodule "toolchains/riscv-tools/riscv-spike-devices"]
 	path = toolchains/riscv-tools/riscv-spike-devices
-	url = https://github.com/ucb-bar/spike-devices.git
+	url = https://gh-proxy.org/https://github.com/ucb-bar/spike-devices.git
 [submodule "toolchains/riscv-tools/riscv-tests"]
 	path = toolchains/riscv-tools/riscv-tests
-	url = https://github.com/riscv-software-src/riscv-tests.git
+	url = https://gh-proxy.org/https://github.com/riscv-software-src/riscv-tests.git
 [submodule "toolchains/riscv-tools/riscv-tools-feedstock"]
 	path = toolchains/riscv-tools/riscv-tools-feedstock
-	url = https://github.com/ucb-bar/riscv-tools-feedstock.git
+	url = https://gh-proxy.org/https://github.com/ucb-bar/riscv-tools-feedstock.git
 [submodule "tools/DRAMSim2"]
 	path = tools/DRAMSim2
 	url = https://github.com/firesim/DRAMSim2.git