mtd: maps: pismo: Convert to i2c's .probe_new()

The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Acked-by: Richard Weinberger <richard@nod.at>
Link: https://lore.kernel.org/lkml/20221118224540.619276-497-uwe@kleine-koenig.org


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@kernel.org>