regulator: Revert "regulator: pfuze100: add enable/disable for switch"

This reverts commit 5fe156f1.

Commit 5fe156f1 ("regulator: pfuze100: add enable/disable for switch")
causes boot regression on some platforms such as imx6sl-evk and
imx6sll-evk.

After this commit the SW4 regulator will be turned
off and since it supplies the DDR voltage on these boards, a
kernel hang is observed.

Revert it to avoid breaking old dtb's.

Fixes: 5fe156f1 ("regulator: pfuze100: add enable/disable for switch")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>