armbian-next: extensions: rename kernel-localmodconfig to just lsmod

- rename `KERNEL_CONFIG_FROM_LSMOD` to just `LSMOD` too
- default `LSMOD` to `${BOARD}`
- and make it "better"

extensions/lsmod.sh

@@ -0,0 +1,23 @@
+function extension_prepare_config__prepare_localmodconfig() {
+	# If defined, ${LSMOD} can contain a lsmod to apply to the kernel configuration.
+	# to get a file for this run 'lsmod > my_machine.lsmod' and then put it in userpatches/lsmod/
+	declare -g -r LSMOD="${LSMOD:-"${BOARD}"}" # default to the board name
+	display_alert "${EXTENSION}: lsmod enabled" "${LSMOD}" "warn"
+
+	# If there, make sure it exists
+	declare -g -r lsmod_file="${SRC}/userpatches/lsmod/${LSMOD}.lsmod"
+	if [[ ! -f "${lsmod_file}" ]]; then
+		exit_with_error "Can't find lsmod file ${lsmod_file}, create it by running lsmod on target HW or configure with LSMOD=xxx"
+	fi
+}
+
+# This needs much more love than this. can be used to make "light" versions of kernels, that compile 3x-5x faster or more
+function custom_kernel_config_post_defconfig__apply_localmodconfig() {
+	if [[ -f "${lsmod_file}" ]]; then
+		display_alert "${EXTENSION}: running localmodconfig on Kernel tree" "${LSMOD}" "warn"
+		run_kernel_make "LSMOD=${lsmod_file}" localmodconfig "> /dev/null" # quoted redirect to hide output even from logfile, it's way too long. stderr still shows
+	else
+		display_alert "${EXTENSION}: lsmod file disappeared?" "${lsmod_file}" "err"
+		return 1 # exit with an error; this is not what the user expected
+	fi
+}