SRC: Files structure change and add Xtensa optimized versions

This patch moves generic common code to src.c/h from src_core.c/h and
places generic C optimized filter to src_generic.c. The HiFi EP
version is in src_hifi2ep.c and HiFi3 version is in src_hifi3.c. Use of
the Xtensa optimized versions require xt-xcc compiler.

The non-used SRC in/out rates query code is removed. The 24 bit
coefficients were replaced by 32 bit coefficients those are compatible
with Xtensa fractional integer types.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@linux.intel.com>

Author: singalsu

src/audio/Makefile.am

@@ -1006,7 +1006,9 @@ libaudio_a_SOURCES = \
 	fir.c \
 	tone.c \
 	src.c \
-	src_core.c \
+	src_generic.c \
+	src_hifi2ep.c \
+	src_hifi3.c \
 	mixer.c \
 	mux.c \
 	volume.c \