i8k: Tell gcc that *regs gets clobbered

i8k: Tell gcc that *regs gets clobbered

More recent GCC caused the i8k driver to stop working, on Slackware
compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it didn't
work anymore, meaning the driver didn't load or gave total nonsensical
output.

As it turned out the asm(..) statement forgot to mention it modifies the
*regs variable.

Credits to Andi Kleen and Andreas Schwab for providing the fix.

Signed-off-by: Jim Bos <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Andreas Schwab <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>