drivers: wifi: esp: do not wait at the end of ESP chip reset

esp_reset() is called from net_if init function, which holds net_if lock
after commit 24b49f43 ("net: if: Add locking"). At the end of
esp_reset() there is a blocking wait on `sem_if_up` semaphore. This
semaphore can be release only by esp_init_work(). esp_init_work()
however blocks on net_if operations, because net_if init function (which
invokes esp_reset() underneath) is still holding net_if lock. As a
result there is a deadlock, because esp_reset() and esp_init_work() are
both waiting on each other.

Remove waiting for `sem_if_up`, so that net_if init can exit and release
net_if lock.

Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>