MIPS: PowerTV: use free_reserved_area() to simplify code

Use common help function free_reserved_area() to simplify code.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: linux-mm@kvack.org
Cc: linux-arch@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5248/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>