staging: r8188eu: remove haldata's EEPROMSubCustomerID

It is used only in a (disabled) debug print.

We can now remove two functions that parsed eeprom info and populated
haldata components.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211111212644.9011-3-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>