Makefile: Remove mkinitcpio-archiso specific targets

Makefile:
Remove all code specific to mkinitcpio-archiso.
Allow overriding PREFIX (defaults to /usr/local).
Gather scripts to check more generically.
Add abstractions for installation directories.

Makefile

 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-INSTALL_FILES=$(wildcard archiso/initcpio/install/*)
-HOOKS_FILES=$(wildcard archiso/initcpio/hooks/*)
-SCRIPT_FILES=$(wildcard archiso/initcpio/script/*)
-
-INSTALL_DIR=$(DESTDIR)/usr/lib/initcpio/install
-HOOKS_DIR=$(DESTDIR)/usr/lib/initcpio/hooks
-SCRIPT_DIR=$(DESTDIR)/usr/lib/initcpio
+PREFIX ?= /usr/local
+BIN_DIR=$(DESTDIR)$(PREFIX)/bin
+DOC_DIR=$(DESTDIR)$(PREFIX)/share/doc/archiso
+PROFILE_DIR=$(DESTDIR)$(PREFIX)/share/archiso
 
 DOC_FILES=$(wildcard docs/*) $(wildcard *.rst)
-
-DOC_DIR=$(DESTDIR)/usr/share/doc/archiso
-
+SCRIPT_FILES=$(wildcard archiso/*) $(wildcard scripts/*.sh) $(wildcard .gitlab/ci/*.sh) \
+             $(wildcard configs/*/profiledef.sh) $(wildcard configs/*/airootfs/usr/local/bin/*)
 
 all:
 
-check: lint
-
-lint:
-	shellcheck -s bash archiso/mkarchiso \
-	                   $(wildcard scripts/*.sh) \
-	                   $(wildcard .gitlab/ci/*.sh) \
-	                   $(INSTALL_FILES) \
-	                   $(wildcard configs/*/build.sh) \
-	                   $(wildcard configs/*/profiledef.sh) \
-	                   configs/releng/airootfs/root/.automated_script.sh \
-	                   configs/releng/airootfs/usr/local/bin/choose-mirror \
-	                   configs/releng/airootfs/usr/local/bin/livecd-sound
-	shellcheck -s dash $(HOOKS_FILES) $(SCRIPT_FILES)
+check: shellcheck
 
-install: install-program install-examples install-doc
+shellcheck:
+	shellcheck -s bash $(SCRIPT_FILES)
 
-install-program:
-	install -vDm 755 archiso/mkarchiso -t "$(DESTDIR)/usr/bin/"
-	install -vDm 755 scripts/run_archiso.sh "$(DESTDIR)/usr/bin/run_archiso"
+install: install-scripts install-profiles install-doc
 
-install-initcpio:
-	install -d $(SCRIPT_DIR) $(HOOKS_DIR) $(INSTALL_DIR)
-	install -m 755 -t $(SCRIPT_DIR) $(SCRIPT_FILES)
-	install -m 644 -t $(HOOKS_DIR) $(HOOKS_FILES)
-	install -m 644 -t $(INSTALL_DIR) $(INSTALL_FILES)
+install-scripts:
+	install -vDm 755 archiso/mkarchiso -t "$(BIN_DIR)/"
+	install -vDm 755 scripts/run_archiso.sh "$(BIN_DIR)/run_archiso"
 
-install-examples:
-	install -d -m 755 $(DESTDIR)/usr/share/archiso/
-	cp -a --no-preserve=ownership configs $(DESTDIR)/usr/share/archiso/
+install-profiles:
+	install -d -m 755 $(PROFILE_DIR)
+	cp -a --no-preserve=ownership configs $(PROFILE_DIR)/
 
 install-doc:
 	install -vDm 644 $(DOC_FILES) -t $(DOC_DIR)
 
-.PHONY: check install install-program install-initcpio install-examples install-doc lint
+.PHONY: check install install-doc install-profiles install-scripts shellcheck