tslib: Use the release tarball

Add a hash file since the release tarball has been uploaded from the
maintainer.

Signed-off-by: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/tslib/tslib.hash

@@ -0,0 +1,2 @@
+# Locally generated
+sha256  121750e9ae0f05ce840ab8dbefdae1297258f0a69dd1967f55c40ac6e87d5ee9  tslib-1.1.tar.gz

package/tslib/tslib.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 TSLIB_VERSION = 1.1
-TSLIB_SITE = $(call github,kergoth,tslib,$(TSLIB_VERSION))
+TSLIB_SITE = https://github.com/kergoth/tslib/releases/download/$(TSLIB_VERSION)/
 TSLIB_LICENSE = GPL, LGPL
 TSLIB_LICENSE_FILES = COPYING