accel/ivpu: Apply minor code style cleanups to align with kernel style

accel/ivpu: Apply minor code style cleanups to align with kernel style

Replace direct import_attach test with drm_gem_is_imported()
in ivpu_bo_bind().

Replace kzalloc(sizeof(*bo), GFP_KERNEL) with kzalloc_obj()
in ivpu_gem_create_object().

Remove unnecessary cast to bool in ivpu_dbg_bo().

No functional changes.

Reviewed-by: Maciej Falkowski <maciej.falkowski@linux.intel.com>
Signed-off-by: Karol Wachowski <karol.wachowski@linux.intel.com>
Link: https://patch.msgid.link/20260310120736.3341679-1-karol.wachowski@linux.intel.com