* without this tune-xscale and tune-arm926ejs were both creating
packages in armv5te feed, but each with different -mtune, with
OEBasicHash enabled it was causing each package to rebuild with new
-mtune after MACHINE switch, but that doesn't make sense with output
stored in the same armv5te feed
* this makes different feed for each -mtune, but more generic one to be
selected with DEFAULTTUNE
* tune-iwmmxt and tune-ep9312 were already using this, just move it
bellow AVAILTUNES and use ARMPKGARCH_tune-foo syntax
* tune-cortexr4 and tune-cortexm3 are using armv7r/armv7m as ARMPKGARCH
because there isn't another tune to use the same -march
(From OE-Core rev: cffda9a821a3b83a8529d643c567859e091c6846)
Signed-off-by: Andrei Gherzan <andrei@gherzan.ro>