build: configure: make sure we can include C headers in assembly

Set ASSEMBLY when we are building .S files so that C headers can
be included.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

configure.ac

@@ -21,6 +21,10 @@ AC_CANONICAL_HOST
 # General compiler flags
 CFLAGS="${CFLAGS:+$CFLAGS } -O2 -g -Wall -Werror -Wl,-EL -fno-inline-functions -nostdlib -Wmissing-prototypes"
 
+# General assembler flags
+ASFLAGS="-DASSEMBLY"
+AC_SUBST(ASFLAGS)
+
 # Cross compiler tool libgcc and headers
 AC_ARG_WITH([root-dir],
         AS_HELP_STRING([--with-root-dir], [Specify location of cross gcc libraries and headers]),

src/arch/xtensa/Makefile.am

@@ -23,6 +23,7 @@ libreset_a_SOURCES = \
 
 libreset_a_CCASFLAGS = \
 	$(ARCH_INCDIR) \
+	$(ASFLAGS) \
 	$(ARCH_ASFLAGS) \
 	$(PLATFORM_INCDIR) \
 	-mtext-section-literals
@@ -42,6 +43,7 @@ reef_CFLAGS = \
 
 reef_CCASFLAGS = \
 	$(ARCH_INCDIR) \
+	$(ASFLAGS) \
 	$(ARCH_ASFLAGS) \
 	$(PLATFORM_INCDIR)