package/rockchip-mali: fix build failure due to missing URL

Github rockchip-linux doesn't provide libmali repository anymore and the
only up-to-date and maintained repository I've found is JeffyCN/mirrors
branch libmali that provide the identical situtation we were at with
previous repository, so let's switch to JeffyCN repository. This fixes
a build failure while trying to install rockchip-mali.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
(cherry picked from commit 8c25838b53e6e469839a71df5da610378e87aa40)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/rockchip-mali/rockchip-mali.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 ROCKCHIP_MALI_VERSION = 721653b5b3b525a4f80d15aa7e2f9df7b7e60427
-ROCKCHIP_MALI_SITE = $(call github,rockchip-linux,libmali,$(ROCKCHIP_MALI_VERSION))
+ROCKCHIP_MALI_SITE = $(call github,JeffyCN,mirrors,$(ROCKCHIP_MALI_VERSION))
 ROCKCHIP_MALI_LICENSE = Proprietary
 ROCKCHIP_MALI_LICENSE_FILES = END_USER_LICENCE_AGREEMENT.txt
 ROCKCHIP_MALI_INSTALL_STAGING = YES