interconnect: Make icc_provider_del() return void

All users ignore the return value of icc_provider_del(). Consequently
make it not return an error code.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220718121409.171773-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Georgi Djakov <djakov@kernel.org>