boot/optee-os: license files hashes only valid for latest version

We can only know the details of the license files for known versions.  For
custom, older or newer versions, the license files may change, or may be
moved around.

So, do for optee-os as was done for other packages in the recent past,
and only define the list of license files for the latest version.

Reported-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Markus Mayer <mmayer@broadcom.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

boot/optee-os/optee-os.mk

@@ -6,7 +6,9 @@
 
 OPTEE_OS_VERSION = $(call qstrip,$(BR2_TARGET_OPTEE_OS_VERSION))
 OPTEE_OS_LICENSE = BSD-2-Clause
+ifeq ($(BR2_TARGET_OPTEE_OS_LATEST),y)
 OPTEE_OS_LICENSE_FILES = LICENSE
+endif
 
 OPTEE_OS_INSTALL_STAGING = YES
 OPTEE_OS_INSTALL_IMAGES = YES