hwrng: omap - Convert release_resource to release_region/release_mem_region

Request_region should be used with release_region, not release_resource.

The local variable mem, storing the result of request_mem_region, is
dropped and instead the pointer res is stored in the drvdata field of the
platform device.  This information is retrieved in omap_rng_remove to
release the region.  The drvdata field is not used elsewhere.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,E;
@@
(
*x = request_region(...)
|
*x = request_mem_region(...)
)
... when != release_region(x)
    when != x = E
* release_resource(x);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>