x86/sev: Include fpu/xcr.h

Include the header which only provides the XCR accessors. That's all what
is needed here.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.896573039@linutronix.de

arch/x86/kernel/sev.c

@@ -23,7 +23,7 @@
 #include <asm/stacktrace.h>
 #include <asm/sev.h>
 #include <asm/insn-eval.h>
-#include <asm/fpu/internal.h>
+#include <asm/fpu/xcr.h>
 #include <asm/processor.h>
 #include <asm/realmode.h>
 #include <asm/traps.h>