x86/fpu: Rename fpu/xsave.h to fpu/xstate.h

'xsave' is an x86 instruction name to most people - but xsave.h is
about a lot more than just the XSAVE instruction: it includes
definitions and support, both internal and external, related to
xstate and xfeatures support.

As a first step in cleaning up the various xstate uses rename this
header to 'fpu/xstate.h' to better reflect what this header file
is about.

Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/crypto/cast6_avx_glue.c

@@ -37,7 +37,7 @@
 #include <crypto/lrw.h>
 #include <crypto/xts.h>
 #include <asm/xcr.h>
-#include <asm/fpu/xsave.h>
+#include <asm/fpu/xstate.h>
 #include <asm/crypto/glue_helper.h>
 
 #define CAST6_PARALLEL_BLOCKS 8