CircleCI & Makefile: fixes needed for coreboot-git/cache reuse

CircleCI: depend on NV41 for save_cache
Makefile: consider that coreboot-git is now shared between forks on x86 (Nitrokey/Purism share build/x86/coreboot-git now)

Addressesses requested change at linuxboot#1417 (review)

.circleci/config.yml

@@ -215,31 +215,31 @@ workflows:
 # version. The last board in the sequence is the dependency
 # for the parallel boards built at the end, and also save_cache.
 
-      # Coreboot 4.19
+      # coreboot 4.19
       - build_and_persist:
           name: x230-hotp-maximized
           target: x230-hotp-maximized
           subcommand: ""
           requires:
             - prep_env
 
-      # Coreboot 4.17
+      # coreboot-git librems
       - build_and_persist:
           name: librem_14
           target: librem_14
           subcommand: ""
           requires:
             - x230-hotp-maximized
 
-      # Coreboot Nitropads
+      # coreboot-git Nitropads on top of coreboot-git librems
       - build_and_persist:
           name: nitropad-nv41
           target: nitropad-nv41
           subcommand: ""
           requires:
             - librem_14
 
-      # Coreboot for Talos (PPC)
+      # coreboot-git Talos II (PPC)
       - build_and_persist:
           name: talos-2
           arch: ppc64
@@ -251,7 +251,6 @@ workflows:
       #Cache one workspace per architecture. Make sure workspace caches are chainloaded and the last in chain for an arch is saved.
       - save_cache:
           requires:
-            - librem_14
             - talos-2
             - nitropad-nv41
 
@@ -506,7 +505,7 @@ workflows:
           requires:
             - x230-hotp-maximized
 
-#Coreboot 4.17 boards
+#coreboot-git librem boards
       - build:
           name: librem_13v2
           target: librem_13v2
@@ -549,6 +548,7 @@ workflows:
           requires:
             - librem_14
 
+#coreboot-git Nitrokey NV
       - build:
           name: nitropad-ns50
           target: nitropad-ns50

Makefile

@@ -302,7 +302,9 @@ define define_module =
 		echo -n '$($1_repo)|$($1_commit_hash)' > "$$@"; \
 	elif [ "$$$$(cat "$$@")" != '$($1_repo)|$($1_commit_hash)' ]; then \
 		echo "Switching $1 to $($1_repo) at $($1_commit_hash)" && \
-		git -C "$(build)/$($1_base_dir)" fetch $($1_repo) $($1_commit_hash) && \
+		git -C "$(build)/$($1_base_dir)" reset --hard HEAD^ && \
+		git -C "$(build)/$($1_base_dir)" remote set-url origin $($1_repo) && \
+		git -C "$(build)/$($1_base_dir)" checkout origin > /dev/null 2>&1 && \
 		git -C "$(build)/$($1_base_dir)" reset --hard $($1_commit_hash) && \
 		git -C "$(build)/$($1_base_dir)" clean -df && \
 		git -C "$(build)/$($1_base_dir)" clean -dffx payloads util/cbmem && \