staging: r8188eu: remove eeprom function prototypes

Remove prototypes for non-existing eeprom functions. It seems that r8188eu
has efuses but no eeprom.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220709171000.180481-4-martin@kaiser.cx


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