build: Do not define -DPIC longer through build system

Now all code relies upon __PIC__ flag defined by compiler, so
it does not need to explicitly define the PIC macro through build system

Signed-off-by: Carmelo Amoroso <carmelo.amoroso@st.com>

Rules.mak

@@ -228,7 +228,7 @@ CPU_CFLAGS-$(UCLIBC_FORMAT_FLAT_SEP_DATA) += -msep-data
 CPU_LDFLAGS-$(ARCH_LITTLE_ENDIAN) += -Wl,-EL
 CPU_LDFLAGS-$(ARCH_BIG_ENDIAN)    += -Wl,-EB
 
-PICFLAG-y := -fPIC -DPIC
+PICFLAG-y := -fPIC
 PICFLAG-$(UCLIBC_FORMAT_FDPIC_ELF) := -mfdpic
 PICFLAG := $(PICFLAG-y)
 PIEFLAG_NAME:=-fPIE