Add an option to run 'make mod2yesconfig'

It is sometimes useful to build all modules into vmlinux. Add an option
'MOD2YES=1' that runs 'make mod2yesconfig' after all kernel config
steps.

Author: rnav

README.md

@@ -105,6 +105,8 @@ The log will be in eg. `output/ppc64le@ubuntu@21.10/ppc64le_defconfig/sparse.log
 
 To build modules pass `MODULES=1`
 
+To convert all modules to builtin, pass `MOD2YES=1`.
+
 To build with clang pass `CLANG=1`, only works using the Ubuntu `21.10` images.
 
 For a quiet build pass `QUIET=1`, for verbose pass `VERBOSE=1`.

build/scripts/build.sh

@@ -105,6 +105,10 @@ if [[ "$task" == "kernel" ]]; then
 	cmd+="-e MERGE_CONFIG=$MERGE_CONFIG "
     fi
 
+    if [[ -n "$MOD2YES" ]]; then
+	cmd+="-e MOD2YES=1 "
+    fi
+
     if [[ -n "$CLANG" ]]; then
         cmd+="-e CLANG=1 "
     fi

build/scripts/container-build.sh

@@ -78,6 +78,10 @@ if [[ "$1" == "kernel" ]]; then
 
     rc=$?
 
+    if [[ -n "$MOD2YES" ]]; then
+        (set -x; make $verbose $quiet "$cc" mod2yesconfig)
+    fi
+
     if [[ $rc -eq 0 ]]; then
         if [[ -n "$SPARSE" ]]; then
             rm -f /output/sparse.log