uml: eliminate floating point state from register file

The floating point fields in the pt_regs register file aren't used, so they
are deleted.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>