drivers/regulator: fix when type is different from REGULATOR_VOLTAGE or REGULATOR_CURRENT

When regulator_desc->type is something different from REGULATOR_VOLTAGE or REGULATOR_CURRENT
the if should probably return ERR_PTR(-EINVAL)

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/

)

@@ expression E; constant C; @@
(
- !E == C
+ E != C
)

Signed-off-by: Diego Liziero <diegoliz@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>