stm32mp1: remove useless compilation flags

On AARCH32, thumb is used by default, no need to redefine it.
As all our binaries are compiled with thumb, interwork is not needed.
The binaries compiled with or without those flags are the same,
except of course for the date.
Signed-off-by: Yann Gautier <yann.gautier@st.com>

plat/st/stm32mp1/platform.mk

@@ -83,10 +83,6 @@ BL2_SOURCES		+=	common/desc_image_load.c				\
 				plat/st/stm32mp1/plat_bl2_mem_params_desc.c		\
 				plat/st/stm32mp1/plat_image_load.c
 
-# For memory footprint optimization, build with thumb and interwork support
-ASFLAGS			+=	-mthumb -mthumb-interwork
-TF_CFLAGS		+=	-mthumb -mthumb-interwork
-
 # Macros and rules to build TF binary
 STM32_TF_ELF_LDFLAGS	:=	--hash-style=gnu --as-needed
 STM32_DT_BASENAME	:=	$(STM32_DTB_FILE_NAME:.dtb=)