i2c: take address space into account when checking for used addresses

It is not enough to compare the plain address value, we also need to
check the flags enabling a different address space. E.g. it is valid to
have address 0x50 as a 7-bit address and 0x050 as 10-bit address on the
same bus. Same for addresses when we are the slave.

Tested-by: Andrey Danin <danindrey@mail.ru>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>