arm-defaults.inc: Tweak DEFAULTTUNE with anonymous pything instead of overrides

This will avoid making entries for every machine on earch that is based
on armv7a and would like to use angstrom and its feeds, secondly it
makes it unified baseline for all armv7a machines and not divide it
with cortex-A8, cortex-A9 and so on
Above all brings sanity

Signed-off-by: Khem Raj <raj.khem@gmail.com>

conf/distro/include/arm-defaults.inc

@@ -1,9 +1,22 @@
-# Cortex-A8 machines:
+# This function changes the default tune for machines which
+# are based on armv7a to use common tune value, note that we enforce hard-float
+# which is default on Ångström for armv7+
+# so if you have one of those machines which are armv7a but can't support
+# hard-float, please change tune = 'armv7athf' to tune = 'armv7at'
+# below but then this is for your own distro, Ångström will not support
+# it
+# - Khem
 
-DEFAULTTUNE_beagleboard = "cortexa8hf-neon"
-DEFAULTTUNE_beaglebone = "cortexa8hf-neon"
-DEFAULTTUNE_overo = "cortexa8hf-neon"
-
-# Cortex-A9 machines:
-DEFAULTTUNE_pandaboard = "cortexa9hf-neon"
+def arm_tune_handler(d):
+    features = d.getVar('TUNE_FEATURES', True).split()
+    if 'armv7a' in features:
+        tune = 'armv7athf'
+        if 'bigendian' in features:
+            tune += 'b'
+        if 'neon' in features:
+            tune += '-neon'
+    else:
+        tune = d.getVar('DEFAULTTUNE', True)
+    return tune
 
+DEFAULTTUNE := "${@arm_tune_handler(d)}"