powerpc: Don't include asm/ppc_asm.h in other headers

asm/ppc_asm.h is not needed in any of the header it is included.

It is only needed by irq.c. Include it there and remove it from
other headers.

word-at-a-time.h only need ex_table.h, so include it instead.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e2d7b96547037f852c7ed164e4f79e8918c2607a.1651828453.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/io.h

@@ -33,7 +33,6 @@ extern struct pci_dev *isa_bridge_pcidev;
 #include <asm/delay.h>
 #include <asm/mmiowb.h>
 #include <asm/mmu.h>
-#include <asm/ppc_asm.h>
 
 #define SIO_CONFIG_RA	0x398
 #define SIO_CONFIG_RD	0x399

arch/powerpc/include/asm/uaccess.h

@@ -2,7 +2,6 @@
 #ifndef _ARCH_POWERPC_UACCESS_H
 #define _ARCH_POWERPC_UACCESS_H
 
-#include <asm/ppc_asm.h>
 #include <asm/processor.h>
 #include <asm/page.h>
 #include <asm/extable.h>

arch/powerpc/include/asm/word-at-a-time.h

@@ -7,7 +7,7 @@
 
 #include <linux/kernel.h>
 #include <asm/asm-compat.h>
-#include <asm/ppc_asm.h>
+#include <asm/extable.h>
 
 #ifdef __BIG_ENDIAN__
 

arch/powerpc/kernel/irq.c

@@ -65,6 +65,7 @@
 #include <asm/smp.h>
 #include <asm/hw_irq.h>
 #include <asm/softirq_stack.h>
+#include <asm/ppc_asm.h>
 
 #ifdef CONFIG_PPC64
 #include <asm/paca.h>