ramips: set -march=24kec for rt305x and rt3883 to enable use of DSP extension

All known rt305x and rt3883 implementations support at
least the 24kec instruction set which includes the DSP
extension. For rt288x, the previous value mips32r2 is
kept.

The cpu target is now set per sub-archtecture, according
to cpu-feature-overrides.h of each SoC family.

[juhosg: define ARCH_PACKAGES variable for rt305x/rt3883
in order to differentiate the packages compiled with
the 24Kec option.]

Signed-off-by: Daniel Golle <dgolle@allnet.de>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 35853

target/linux/ramips/Makefile

@@ -10,7 +10,7 @@ ARCH:=mipsel
 BOARD:=ramips
 BOARDNAME:=Ralink RT288x/RT3xxx
 SUBTARGETS:=rt288x rt305x rt3883
-CFLAGS:=-Os -pipe -mips32r2 -mtune=mips32r2 -fno-caller-saves -mno-branch-likely
+CFLAGS:=-Os -pipe -fno-caller-saves -mno-branch-likely
 FEATURES:=squashfs
 
 LINUX_VERSION:=3.7.9

target/linux/ramips/rt288x/target.mk

@@ -4,6 +4,7 @@
 
 SUBTARGET:=rt288x
 BOARDNAME:=RT288x based boards
+CFLAGS+= -mips32r2 -mtune=mips32r2
 
 define Target/Description
 	Build firmware images for Ralink RT288x based boards.

target/linux/ramips/rt305x/target.mk

@@ -4,6 +4,8 @@
 
 SUBTARGET:=rt305x
 BOARDNAME:=RT305x based boards
+ARCH_PACKAGES:=ramips_24kec
+CFLAGS+= -march=24kec
 
 define Target/Description
 	Build firmware images for Ralink RT305x based boards.

target/linux/ramips/rt3883/target.mk

@@ -4,6 +4,8 @@
 
 SUBTARGET:=rt3883
 BOARDNAME:=RT3662/RT3883 based boards
+ARCH_PACKAGES:=ramips_24kec
+CFLAGS+= -march=24kec
 
 define Target/Description
 	Build firmware images for Ralink RT3662/RT3883 based boards.