spi: bcm63xx-hsspi: checking for ERR_PTR instead of NULL
devm_request_and_ioremap() returns NULL on error, it doesn't return an
ERR_PTR(). This patch fixes it by switching to devm_ioremap_resource()
which is the prefered function anyway.
Fixes: 142168eba9dc ('spi: bcm63xx-hsspi: add bcm63xx HSSPI driver') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Jonas Gorski <jogo@openwrt.org> Signed-off-by: Mark Brown <broonie@linaro.org>