Fix r2 arch plugin for radare2 >= 5.8 RArchPlugin API

- Rewrote plugin using RArchPlugin (decode callback)
- Matches z80 reference plugin structure
- Tested against r2 6.1.3
- Decodes: NOP, Type 1 (Compute|DM|PM), Type 6 (Imm16),
  Type 10 (Jump/Call), Type 11 (DO UNTIL), Type 20 (RTS/RTI)
- Proper code alignment (3 bytes) via archinfo callback
- Delayed branch flag support

r2plugin/Makefile

@@ -1,14 +1,24 @@
 NAME=asm_adsp219x
-R2_PLUGIN_PATH=$(shell r2 -H R2_USER_PLUGINS)
+R2_PLUGINS=$(shell r2 -H R2_USER_PLUGINS)
+R2_INCDIR=$(shell r2 -H R2_INCDIR)
+R2_LIBDIR=$(shell r2 -H R2_LIBDIR)
 
 all: $(NAME).so
 
 $(NAME).so: $(NAME).c
-	gcc -shared -Wall -O2 -fPIC $(shell pkg-config --cflags --libs r_asm) $< -o $@
+	gcc -shared -Wall -O2 -fPIC \
+		-I$(R2_INCDIR) -I$(R2_INCDIR)/sdb \
+		-L$(R2_LIBDIR) \
+		$(NAME).c -o $@ -lr_arch -lr_util
 
 install: $(NAME).so
-	mkdir -p $(R2_PLUGIN_PATH)
-	cp $(NAME).so $(R2_PLUGIN_PATH)
+	mkdir -p $(R2_PLUGINS)
+	cp -f $(NAME).so $(R2_PLUGINS)/
+
+uninstall:
+	rm -f $(R2_PLUGINS)/$(NAME).so
 
 clean:
 	rm -f $(NAME).so
+
+.PHONY: all install uninstall clean