libiconv-full: Makefile polishing

Added PKG_INSTALL to avoid using an explicit define Build/Compile

Added PKG_BUILD_PARALLEL for faster compilation.

Removed TARGET_CLAFGS. They are no longer necessary.
fPIC is default now. So is gnu99. -DUSE_DOS is a hack to include old
and mostly unused conversions.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

package/libs/libiconv-full/Makefile

@@ -21,6 +21,8 @@ PKG_LICENSE:=LGPL-2.1-or-later
 PKG_LICENSE_FILES:=COPYING.LIB
 
 PKG_FIXUP:=patch-libtool
+PKG_INSTALL:=1
+PKG_BUILD_PARALLEL:=1
 
 include $(INCLUDE_DIR)/package.mk
 
@@ -53,21 +55,12 @@ define Package/iconv
   TITLE+= utility
 endef
 
-TARGET_CFLAGS += $(FPIC) -DUSE_DOS -std=gnu89
-
 CONFIGURE_ARGS += \
 	--enable-shared \
 	--enable-static \
 	--disable-rpath \
 	--enable-relocatable
 
-define Build/Compile
-	$(MAKE) -C $(PKG_BUILD_DIR) \
-		CC="$(TARGET_CC)" \
-		DESTDIR="$(PKG_INSTALL_DIR)" \
-		install
-endef
-
 define Build/InstallDev
 	$(INSTALL_DIR) $(1)/usr/lib/libiconv-full/include
 	$(CP) $(PKG_INSTALL_DIR)/usr/include/iconv.h $(1)/usr/lib/libiconv-full/include/