tinycompress: clarify dual-license wording

tinycompress: clarify dual-license wording

There were reports of confusion in legal circles introduced by the wording
"tinycompress is provided under LGPL and BSD dual license" in the README.

Clarify with the addition of the wording traditionally used for dual licenses:

"This file is provided under a dual BSD/LGPLv2.1 license.  When using or
redistributing this file, you may do so under either license"

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>