gpu: host1x: Fix an error handling path in 'host1x_probe()'

Add the missing 'host1x_bo_cache_destroy()' call in the error handling
path of the probe, as already done in the remove function.

In order to simplify the error handling, move the 'host1x_bo_cache_init()'
call after all the devm_ function.

Fixes: 1f39b1df ("drm/tegra: Implement buffer object cache")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Thierry Reding <treding@nvidia.com>