[M85 Migration][Rendering] Force gpu acceleration

[M85 Migration][Rendering] Force gpu acceleration

Chromium-efl port does not support s/w mode. So we need to set h/w
mode before creating elm_window. To do this, make constructor function
which is called at library loading time and set "ELM_ACCEL=hw" here.
If not, native app which does not call elm_config_accel_preference_set()
function will fail to execute.

Reference: https://review.tizen.org/gerrit/220875/

Change-Id: I0f7bb1b53b95dcd5390ca1b4c8b578ac67a6afbf
Signed-off-by: Chandan Padhi <c.padhi@samsung.com>
(cherry picked from commit af5cbc2f38633fbe818fd6421e2fbe5525076970)