mfd: Add devm_mfd_add_devices() in list of managed interfaces

Add devm wrappers for the mfd_add_devices() in the list of managed
interfaces.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

Documentation/driver-model/devres.txt

@@ -317,6 +317,9 @@ MEM
   devm_kvasprintf()
   devm_kzalloc()
 
+MFD
+ devm_mfd_add_devices()
+
 PCI
   pcim_enable_device()	: after success, all PCI ops become managed
   pcim_pin_device()	: keep PCI device enabled after release