afboot-stm32: fix problem with fdpic toolchain

package/afboot-stm32/Makefile

@@ -4,7 +4,7 @@
 include $(ADK_TOPDIR)/rules.mk
 
 PKG_NAME:=		afboot-stm32
-PKG_VERSION:=		8e9e03159ce47629d40dbed4c50c1879b69bb197
+PKG_VERSION:=		3566acd582e5536fb60864281788a30f5527df2d
 PKG_RELEASE:=		1
 PKG_DESCR:=		bootloader for stm32 devices
 PKG_SECTION:=		base/boot

package/afboot-stm32/patches/patch-Makefile

@@ -0,0 +1,10 @@
+--- afboot-stm32-3566acd582e5536fb60864281788a30f5527df2d.orig/Makefile	2020-11-11 22:52:18.000000000 +0100
++++ afboot-stm32-3566acd582e5536fb60864281788a30f5527df2d/Makefile	2020-11-11 22:56:16.737522477 +0100
+@@ -13,6 +13,7 @@ DTB_ADDR?=0x08004000
+ CFLAGS := -mthumb -mcpu=cortex-m4
+ CFLAGS += -ffunction-sections -fdata-sections
+ CFLAGS += -Os -std=gnu99 -Wall
++CFLAGS += -fno-builtin -mno-fdpic
+ LINKERFLAGS := -nostartfiles --gc-sections
+ 
+ obj-y += gpio.o mpu.o qspi.o start_kernel.o