hostapd: Make install path configurable

Makefile always installs to /usr/local/bin and on some platforms,
/usr/local/bin is not in default search path. Modify the Makefile such
that bin path can be configurable so that build system can pass
appropriate path for installation. If bin path is not specified then by
default binaries are installed in /usr/local/bin.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

hostapd/Makefile

@@ -9,6 +9,8 @@ endif
 CFLAGS += -I$(abspath ../src)
 CFLAGS += -I$(abspath ../src/utils)
 
+export BINDIR ?= /usr/local/bin/
+
 # Uncomment following line and set the path to your kernel tree include
 # directory if your C library does not include all header files.
 # CFLAGS += -DUSE_KERNEL_HEADERS -I/usr/src/linux/include
@@ -931,9 +933,10 @@ verify_config:
 		exit 1; \
 	fi
 
-install: all
-	mkdir -p $(DESTDIR)/usr/local/bin
-	for i in $(ALL); do cp -f $$i $(DESTDIR)/usr/local/bin/$$i; done
+$(DESTDIR)$(BINDIR)/%: %
+	install -D $(<) $(@)
+
+install: $(addprefix $(DESTDIR)$(BINDIR)/,$(ALL))
 
 ../src/drivers/build.hostapd:
 	@if [ -f ../src/drivers/build.wpa_supplicant ]; then \