activate-caravel: add more paths to `deps/` directory

Add additional directories to the `deps/` directory, to prevent
dependencies from leaking everywhere.

Signed-off-by: Sean Cross <sean@xobs.io>

activate-caravel.sh

diff --git a/activate-caravel.sh b/activate-caravel.sh
index d8eec44..7e75c1e 100644
--- a/activate-caravel.sh
+++ b/activate-caravel.sh
@@ -8,4 +8,7 @@
 
 export OPENLANE_ROOT=$(pwd)/deps/openlane_src
 export PDK_ROOT=$(pwd)/deps/pdks
-export PDK=gf180mcuC
+export PDK=sky130B
+export PRECHECK_ROOT=$(pwd)/deps/precheck
+export CARAVEL_ROOT=$(pwd)/deps/caravel
+export MCW_ROOT=$(pwd)/deps/mgmt_core_wrapper