uhci-platform: use devm_ioremap resource

This patch replaces the memory allocation using request_mem_region and
the ioremap by a single call to managed interface devm_ioremap_reource.
The corresponding calls to release_mem_region and iounmap in the probe
and release functions are now unnecessary and are removed. Also a label
is done away with and linux/device.h is added to make sure the devm_*()
outine declarations are unambiguously available.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>