regulator: 88pm800: fix warning same module names

When building with CONFIG_MFD_88PM800 and CONFIG_REGULATOR_88PM800
enabled as loadable modules, we see the following warning:

warning: same module names found:
  drivers/regulator/88pm800.ko
  drivers/mfd/88pm800.ko

Rework so that the file is named 88pm800-regulator.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index 76e78fa..c15b0b6 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -11,7 +11,7 @@
 obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
 
 obj-$(CONFIG_REGULATOR_88PG86X) += 88pg86x.o
-obj-$(CONFIG_REGULATOR_88PM800) += 88pm800.o
+obj-$(CONFIG_REGULATOR_88PM800) += 88pm800-regulator.o
 obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
 obj-$(CONFIG_REGULATOR_CPCAP) += cpcap-regulator.o
 obj-$(CONFIG_REGULATOR_AAT2870) += aat2870-regulator.o