Spansion S29GL512N simulation model issue

There is a bug in the simulation model V1.3 and eariler. Not try any version newer.

When doing section erase, the RY should be de-asserted right after erase command, but instead, it is de-asserted after 50us.

Note: 50us is the timeout time of erase command. After this time, the device starts real erasing process.

Impact: If the RTL checks if the device is buys or not based on RY, this would give RTL wrong status.

Fix: de-asserte RY right after erase command.