amdgpu/amdgpu_discovery: increase timeout limit for IFWI init

With a timeout of only 1 second, my rx 5700XT fails to initialize,
so this increases the timeout to 2s.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3697


Signed-off-by: Xaver Hugl <xaver.hugl@kde.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 9ed3d7bd)
Cc: stable@vger.kernel.org