See README-turbo.txt: "Most of libjpeg-turbo inherits the non-restrictive, BSD-style license used by libjpeg (see README.) The TurboJPEG/OSS wrapper (both C and Java versions) and associated test programs bear a similar license, which is reproduced below: [standard 3-clause BSD license follows]" README contains the IJG license in the "LEGAL ISSUES" section.
thanks + 28 Dec 2012; Samuli Suominen <ssuominen@gentoo.org> + libjpeg-turbo-1.2.1.ebuild: + Missing legal notice (LICENSE) "IJG" wrt #447282 by Ulrich Müller