Staging: vt6655: Remove unused function vnt_key_init_table

The function vnt_key_init_table is not used anywhere in the kernel.
Therefore, remove the function definition and prototype.
Grepped to find occurences.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>