mfd: mfd-core: Remove mfd_clone_cell()

Providing a subsystem-level API helper seems over-kill just to save a
few lines of C-code.  Previous commits saw us convert mfd_clone_cell()'s
only user over to use a more traditional style of MFD child-device
registration.  Now we can remove the superfluous helper from the MFD API.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

include/linux/mfd/core.h

@@ -115,24 +115,6 @@ struct mfd_cell {
 extern int mfd_cell_enable(struct platform_device *pdev);
 extern int mfd_cell_disable(struct platform_device *pdev);
 
-/*
- * "Clone" multiple platform devices for a single cell. This is to be used
- * for devices that have multiple users of a cell.  For example, if an mfd
- * driver wants the cell "foo" to be used by a GPIO driver, an MTD driver,
- * and a platform driver, the following bit of code would be use after first
- * calling mfd_add_devices():
- *
- * const char *fclones[] = { "foo-gpio", "foo-mtd" };
- * err = mfd_clone_cells("foo", fclones, ARRAY_SIZE(fclones));
- *
- * Each driver (MTD, GPIO, and platform driver) would then register
- * platform_drivers for "foo-mtd", "foo-gpio", and "foo", respectively.
- * The cell's .enable/.disable hooks should be used to deal with hardware
- * resource contention.
- */
-extern int mfd_clone_cell(const char *cell, const char **clones,
-		size_t n_clones);
-
 /*
  * Given a platform device that's been created by mfd_add_devices(), fetch
  * the mfd_cell that created it.