parisc: Remove ioctl.h content picked up from <asm-generic/ioctl.h>.

Now that <asm-generic/ioctl.h> allows overriding of the most commonly
changed macro values, take advantage of that.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>