documentation: update s390 header file paths

Update Documentation/s390/ files to reflect changed header files
locations.

Signed-off-by: Randy Dunlap <[e-mail]>
Cc: Martin Schwidefsky <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/s390/Debugging390.txt

···
 possibilities of these as the instruction is made up of a  0xA opcode & the second byte being
 the syscall number. They are traced using the simple command.
 TR SVC  <Optional value or range>
-the syscalls are defined in linux/include/asm-s390/unistd.h
+the syscalls are defined in linux/arch/s390/include/asm/unistd.h
 e.g. to trace all file opens just do
 TR SVC 5 ( as this is the syscall number of open )
 

Documentation/s390/cds.txt

···
 of them can be found on other Linux platforms implementations too.
 Miscellaneous function prototypes, data declarations, and macro definitions
 can be found in the architecture specific C header file
-linux/include/asm-s390/irq.h.
+linux/arch/s390/include/asm/irq.h.
 
 Overview of CDS interface concepts
 

Documentation/s390/s390dbf.txt

···
 ==================
 
 files: arch/s390/kernel/debug.c
-       include/asm-s390/debug.h
+       arch/s390/include/asm/debug.h
 
 Description:
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