Documentation: devres: fix error about PCI devres

The documentation states that pcim_enable_device() will make "all PCI
ops" managed. This is totally false, only a small subset of PCI
functions become managed that way. Implicating otherwise has caused at
least one bug so far, namely in commit 8558de401b5f ("drm/vboxvideo: use
managed pci functions").

Change the function summary so the functions dangerous behavior becomes
obvious.

Signed-off-by: Philipp Stanner <[e-mail]>
Acked-by: Bjorn Helgaas <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/driver-api/driver-model/devres.rst

···
   devm_pci_remap_cfgspace()	: ioremap PCI configuration space
   devm_pci_remap_cfg_resource()	: ioremap PCI configuration space resource
 
-  pcim_enable_device()		: after success, all PCI ops become managed
+  pcim_enable_device()		: after success, some PCI ops become managed
   pcim_iomap()			: do iomap() on a single BAR
   pcim_iomap_regions()		: do request_region() and iomap() on multiple BARs
   pcim_iomap_regions_request_all() : do request_region() on all and iomap() on multiple BARs