mfd: Fix cs5535 section mismatch

Silence following warnings:
WARNING: drivers/mfd/cs5535-mfd.o(.data+0x20): Section mismatch in
reference from the variable cs5535_mfd_drv to the function
.devinit.text:cs5535_mfd_probe()
The variable cs5535_mfd_drv references
the function __devinit cs5535_mfd_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

WARNING: drivers/mfd/cs5535-mfd.o(.data+0x28): Section mismatch in
reference from the variable cs5535_mfd_drv to the function
.devexit.text:cs5535_mfd_remove()
The variable cs5535_mfd_drv references
the function __devexit cs5535_mfd_remove()
If the reference is valid then annotate the
variable with __exit* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Rename the variable from *_drv to *_driver so
modpost ignore the OK references to __devinit/__devexit
functions.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>