staging: iio: tsl2x7x: rename driver for consistency with other IIO light drivers

This patch renames the tsl2x7x_core.c file to tsl2x7x.c so that the
naming convention is consistent with other IIO light drivers outside
of staging.
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/staging/iio/light/Makefile

@@ -2,4 +2,4 @@
 # Makefile for industrial I/O Light sensors
 #
 
-obj-$(CONFIG_TSL2x7x)	+= tsl2x7x_core.o
+obj-$(CONFIG_TSL2x7x)	+= tsl2x7x.o