i2c: i2c-elektor: Allow building on SMP kernels

i2c: i2c-elektor: Allow building on SMP kernels

In the past, the i2c-elektor driver was broken on SMP. Since then, there
appear to have been some fixes and cleanup work (as pointed out by Wolfram
Sang) to get rid of cli/sti usage and rely on spinlocks instead. Therefore,
let's allow building the driver on SMP kernels again.

I've tested this driver on an SMP kernel on an Alpha UP2000+ for a few days
without any problems.

Signed-off-by: Magnus Lindholm <linmag7@gmail.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>