soc: lantiq: convert to devm_platform_ioremap_resource

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: khilman@baylibre.com
Cc: leoyang.li@nxp.com
Cc: khalasa@piap.pl
Cc: john@phrozen.org
Cc: matthias.bgg@gmail.com
Cc: agross@kernel.org
Cc: bjorn.andersson@linaro.org
Cc: kgene@kernel.org
Cc: krzk@kernel.org
Cc: mripard@kernel.org
Cc: wens@csie.org
Cc: ssantosh@kernel.org
Cc: jun.nie@linaro.org
Cc: shawnguo@kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-mips@vger.kernel.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org