modem/msm-modem: uim-selection: Allow configuring wait time for SIM

Unfortunately it looks like some modem firmwares (or SIM cards?) need more time until the SIM card shows up in the modem. This means that the SIM card might not get configured, making it look like it was not detected at all. On the other hand, having the previous long wait loop affects all devices when there is really no SIM inserted.

The proper solution would be to make it possible to configure SIM cards once they show up (probably in ModemManager). Until then, try to make it possible to workaround this by introducing a configurable delay to wait for the SIM card. It is set to minimal "1 seconds" by default but could be increased by the user if needed to give the modem enough time to detect the SIM card.

This reverts commit 683b543a ("msm-modem-uim-selection: Don't wait for SIM (MR 2470)" but with a new configuration mechanism and a default of 1 second only.

Cc: @TravMurav @calebccff @shad0wfax

Closes !2640