Board configuration for ld tests

[Vidya Praveen]

Hello,

I've sent a patch to remove my recent support for ldflags from board config file
in ld testsuite since ldflags is meant to be the flags to linker through gcc 
driver rather than to ld. In order to support bare linker flags that is passed
to ld directly, I think we need to have a new variable introduced in the board 
config file. If this is acceptable, I would like to propose the name 
'linker_flags' for the same, if I don't get a better suggestion. 

Please let me know your thoughts.

Cheers
VP.