boot/arm-trusted-firmware: add -fno-PIE to CFLAGS

By default the toolchain-wrapper enable -fPIE to the build of all packages.
TF-A support Position Independent Executable(PIE) only in few build cases,
therefore it should be disable by default.
If you still want to enable PIE, TF-A provide a "ENABLE_PIE" build options
that will override the cflags for the supported cases.

Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
[Peter: Only do so for BR2_PIC_PIE]
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

boot/arm-trusted-firmware/arm-trusted-firmware.mk

@@ -50,6 +50,7 @@ endif
 
 ARM_TRUSTED_FIRMWARE_MAKE_OPTS += \
 	CROSS_COMPILE="$(TARGET_CROSS)" \
+	$(if $(BR2_PIC_PIE),CFLAGS="-fno-PIE") \
 	$(call qstrip,$(BR2_TARGET_ARM_TRUSTED_FIRMWARE_ADDITIONAL_VARIABLES)) \
 	PLAT=$(ARM_TRUSTED_FIRMWARE_PLATFORM)