updating submodule heads to point to my own fork

All the bits specific submodules have been forked and this commit updates the
top level bits repo to refer to these forks.

Signed-off-by: Ani Sinha <ani@anisinha.ca>

Author: ani-sinha

.gitmodules

@@ -1,20 +1,25 @@
 [submodule "deps/acpica"]
 	path = deps/acpica
-	url = ../acpica
+	url = git@github.com:ani-sinha/bits-acpica.git
+	branch = bits
 	fetchRecurseSubmodules = true
 [submodule "deps/fdlibm"]
 	path = deps/fdlibm
-	url = ../fdlibm
+	url = git@github.com:ani-sinha/bits-fdlibm.git
+	branch = bits
 	fetchRecurseSubmodules = true
 [submodule "deps/grub"]
 	path = deps/grub
-	url = ../grub
+	url = git@github.com:ani-sinha/bits-grub.git
+	branch = bits
 	fetchRecurseSubmodules = true
 [submodule "deps/libffi"]
 	path = deps/libffi
-	url = ../libffi
+	url = git@github.com:ani-sinha/bits-libffi.git
+	branch = bits
 	fetchRecurseSubmodules = true
 [submodule "deps/python"]
 	path = deps/python
-	url = ../python
+	url = git@github.com:ani-sinha/bits-python.git
+	branch = bits
 	fetchRecurseSubmodules = true