buildroot

configs/olimex_a20_olinuxino_lime_mali: bump kernel version

This commit changes the kernel version used by the
olimex_a20_olinuxino_lime_mali in order to use a version that builds
fine with gcc 5.x. This kernel repository is listed in
https://linux-sunxi.org/Linux#External_links as a possible replacement
for the aging 3.4 sunxi kernel.

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>