ehci-atmel: fix section mismatch warning

Fix the following section mismatch warning:

WARNING: drivers/usb/built-in.o(.data+0x74c): Section mismatch in reference from the variable ehci_atmel_driver to the function .init.text:ehci_atmel_drv_probe()
The variable ehci_atmel_driver references
the function __init ehci_atmel_drv_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,

Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>