aarch32: Allow compiling with soft-float toolchain

ARMv7 and Cortex-A32(ARMv8/aarch32) uses "arm-linux-gnueabi" toolchain which
has both soft-float and hard-float variants and so there could be scenarios
where soft-float toolchain is used.Even though TF-A documentation recommends
to use hard-float toolchain for aarch32 but there are external projects where
we cannot mandate the selection of toolchain and for those projects at least
the build should not fail.

Current TF-A source fails to build with soft-float toolchain because assembler
does not recognizes "vmsr" instruction which is required to enable floating
point unit.

To avoid this piece of code being compiled with soft-float toolchain add
predefined macro guard " __SOFTFP__" exposed by soft-float toolchain.

Change-Id: I76ba40906a8d622dcd476dd36ab4d277a925996c
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>

include/arch/aarch32/el3_common_macros.S

@@ -92,9 +92,14 @@
 	 *
 	 * FPEXC.EN: Enable access to Advanced SIMD and floating point features
 	 *  from all exception levels.
+         *
+         * __SOFTFP__: Predefined macro exposed by soft-float toolchain.
+         *  ARMv7 and Cortex-A32(ARMv8/aarch32) has both soft-float and
+         *  hard-float variants of toolchain, avoid compiling below code with
+         *  soft-float toolchain as "vmsr" instruction will not be recognized.
 	 * ---------------------------------------------------------------------
 	 */
-#if (ARM_ARCH_MAJOR > 7) || defined(ARMV7_SUPPORTS_VFP)
+#if ((ARM_ARCH_MAJOR > 7) || defined(ARMV7_SUPPORTS_VFP)) && !(__SOFTFP__)
 	ldr	r0, =(FPEXC_RESET_VAL | FPEXC_EN_BIT)
 	vmsr	FPEXC, r0
 	isb