Adding submodules for the components GF180MCU PDK.

 * `gf180mcu_fd_pr` - Primitives library.
 * `gf180mcu_fd_sc_mcu7t5v0` - 7 track standard cell library.
 * `gf180mcu_fd_sc_mcu9t5v0` - 9 track standard cell library.
 * `gf180mcu_fd_io` - IO library.
 * `gf180mcu_fd_bd_sram` - Place holder for SRAM build space.

Fixes https://github.com/google/gf180mcu-pdk/issues/2.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

.gitmodules

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..d9f68d1
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,34 @@
+# gf180mcu_fd_pr
+[submodule "libraries/gf180mcu_fd_pr/latest"]
+	path = libraries/gf180mcu_fd_pr/latest
+	url = https://github.com/google/globalfoundries-pdk-libs-gf180mcu_fd_pr.git
+	branch = main
+	shallow = true
+
+# gf180mcu_fd_sc_mcu7t5v0
+[submodule "libraries/gf180mcu_fd_sc_mcu7t5v0/latest"]
+	path = libraries/gf180mcu_fd_sc_mcu7t5v0/latest
+	url = https://github.com/google/globalfoundries-pdk-libs-gf180mcu_fd_sc_mcu7t5v0.git
+	branch = main
+	shallow = true
+
+# gf180mcu_fd_sc_mcu9t5v0
+[submodule "libraries/gf180mcu_fd_sc_mcu9t5v0/latest"]
+	path = libraries/gf180mcu_fd_sc_mcu9t5v0/latest
+	url = https://github.com/google/globalfoundries-pdk-libs-gf180mcu_fd_sc_mcu9t5v0.git
+	branch = main
+	shallow = true
+
+# gf180mcu_fd_io
+[submodule "libraries/gf180mcu_fd_io/latest"]
+	path = libraries/gf180mcu_fd_io/latest
+	url = https://github.com/google/globalfoundries-pdk-libs-gf180mcu_fd_io.git
+	branch = main
+	shallow = true
+
+# gf180mcu_fd_bd_sram
+[submodule "libraries/gf180mcu_fd_bd_sram/latest"]
+	path = libraries/gf180mcu_fd_bd_sram/latest
+	url = https://github.com/google/globalfoundries-pdk-libs-gf180mcu_fd_bd_sram.git
+	branch = main
+	shallow = true

libraries/gf180mcu_fd_bd_sram/latest

diff --git a/libraries/gf180mcu_fd_bd_sram/latest b/libraries/gf180mcu_fd_bd_sram/latest
new file mode 160000
index 0000000..6a03b45
--- /dev/null
+++ b/libraries/gf180mcu_fd_bd_sram/latest
@@ -0,0 +1 @@
+Subproject commit 6a03b4584ffd90905f8a3bdc0327da173d3c8f69

libraries/gf180mcu_fd_io/latest

diff --git a/libraries/gf180mcu_fd_io/latest b/libraries/gf180mcu_fd_io/latest
new file mode 160000
index 0000000..5cc5339
--- /dev/null
+++ b/libraries/gf180mcu_fd_io/latest
@@ -0,0 +1 @@
+Subproject commit 5cc533968c9d03972f92a461af0edc80118b1e9c

libraries/gf180mcu_fd_pr/latest

diff --git a/libraries/gf180mcu_fd_pr/latest b/libraries/gf180mcu_fd_pr/latest
new file mode 160000
index 0000000..92ec4b2
--- /dev/null
+++ b/libraries/gf180mcu_fd_pr/latest
@@ -0,0 +1 @@
+Subproject commit 92ec4b2e5eb193a0c5c2754413d44981c8e17e16

libraries/gf180mcu_fd_sc_mcu7t5v0/latest

diff --git a/libraries/gf180mcu_fd_sc_mcu7t5v0/latest b/libraries/gf180mcu_fd_sc_mcu7t5v0/latest
new file mode 160000
index 0000000..bdae0ba
--- /dev/null
+++ b/libraries/gf180mcu_fd_sc_mcu7t5v0/latest
@@ -0,0 +1 @@
+Subproject commit bdae0ba09c3a21bf4272df11d183775c41879ef0

libraries/gf180mcu_fd_sc_mcu9t5v0/latest

diff --git a/libraries/gf180mcu_fd_sc_mcu9t5v0/latest b/libraries/gf180mcu_fd_sc_mcu9t5v0/latest
new file mode 160000
index 0000000..d8c449c
--- /dev/null
+++ b/libraries/gf180mcu_fd_sc_mcu9t5v0/latest
@@ -0,0 +1 @@
+Subproject commit d8c449c9008610555dd0b0b58f79b99e1b2c6492