x86, xsave: Do not include asm/i387.h in asm/xsave.h

There are no dependencies to asm/i387.h. Instead, if including only
xsave.h the following error occurs:

 .../arch/x86/include/asm/i387.h:110: error: ‘XSTATE_FP’ undeclared (first use in this function)
 .../arch/x86/include/asm/i387.h:110: error: (Each undeclared identifier is reported only once
 .../arch/x86/include/asm/i387.h:110: error: for each function it appears in.)

This patch fixes this.

Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1279651857-24639-2-git-send-email-robert.richter@amd.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>