drm/i915/gtt: fix i915_vm_resv_put() kernel-doc parameter name

drivers/gpu/drm/i915/gt/intel_gtt.h:515: warning: Function parameter or member 'vm' not described in 'i915_vm_resv_put'
drivers/gpu/drm/i915/gt/intel_gtt.h:515: warning: Excess function parameter 'resv' description in 'i915_vm_resv_put'

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/c22e58e770019667980b3617f6e963b76d7e79a7.1683041799.git.jani.nikula@intel.com