staging: rtl8188eu: hal: rtl8188e_hal_init.c: Remove unused function

Remove the function GetEEPROMSize8188E() that is not used anywhere.

This was partially found by using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>