spi/spi-sh: Use devm_ioremap

This patch introduces the use of devm_ioremap and removes the iounmaps
in the probe and remove functions. Also, the labels are renamed to
preserve ordering.

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Mark Brown <broonie@linaro.org>