drm/i915: reverse dp link param selection, prefer fast over wide again

drm/i915: reverse dp link param selection, prefer fast over wide again

... it's this time of the year again. Originally we've frobbed this to
fix up some regressions, but maybe our DP code improved sufficiently
now that we can dare to do again what the spec recommends.

This reverts

commit 2514bc510d0c3aadcc5204056bb440fa36845147
Author: Jesse Barnes <[email protected]>
Date:   Thu Jun 21 15:13:50 2012 -0700

    drm/i915: prefer wide & slow to fast & narrow in DP configs

I'm pretty sure I'll regret this patch, but otoh I expect we won't
make progress here without poking the devil occasionally.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=73694
Cc: [email protected]
Cc: Jesse Barnes <[email protected]>
Tested-by: Itai BEN YAACOV <[email protected]>
Tested-by: David En <[email protected]>
Reported-and-Tested-by: Marcus Bergner <[email protected]>
Reviewed-by: Jani Nikula <[email protected]>
Acked-by: Jesse Barnes <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>