powerpc: Remove duplicate/unnecessary ifdefs

When an ifdef is used in the below manner, second one could be considered
as duplicate.

ifdef DEFINE_A
...code block...
ifdef DEFINE_A <-- This is a duplicate.
...code block...
endif
else
ifndef DEFINE_A <-- This is also duplicate.
...code block...
endif
endif

More details about the script and methods used to find these code
patterns are in cover letter of [1].

Few places in arch/powerpc where this pattern was seen:

paca.h:
Hunk1: Code is under check of CONFIG_PPC64 from line 13, hence the
second CONFIG_PPC64 at line 166 is a duplicate.
Hunk2: CONFIG_PPC_BOOK3S_64 was defined back to back. Merged the two
ifdefs.

asm-offsets.c:
Code is under check of CONFIG_PPC64 from line 176 hence second
CONFIG_PPC64 at line 249 is a duplicate.

powermac/feature.c:
#ifndef CONFIG_PPC64 is used at line 2066. And then in #else again
#ifdef CONFIG_PPC64 is used. Which is a duplicate since in #else means
CONFIG_PPC64 is defined.

xmon.c:
Code is under the check of CONFIG_SMP from line 521 hence the same
check of CONFIG_SMP at line 646 is a duplicate.

No functional change is intended here. It only aims to improve code
readability.

[1] https://lore.kernel.org/all/[e-mail]/

Signed-off-by: Shrikanth Hegde <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://msgid.link/[e-mail]

arch/powerpc/include/asm/paca.h

···
 	u64 kstack;			/* Saved Kernel stack addr */
 	u64 saved_r1;			/* r1 save for RTAS calls or PM or EE=0 */
 	u64 saved_msr;			/* MSR saved here by enter_rtas */
-#ifdef CONFIG_PPC64
 	u64 exit_save_r1;		/* Syscall/interrupt R1 save */
-#endif
 #ifdef CONFIG_PPC_BOOK3E_64
 	u16 trap_save;			/* Used when bad stack is encountered */
 #endif
···
 	/* Non-maskable exceptions that are not performance critical */
 	u64 exnmi[EX_SIZE];	/* used for system reset (nmi) */
 	u64 exmc[EX_SIZE];	/* used for machine checks */
-#endif
-#ifdef CONFIG_PPC_BOOK3S_64
 	/* Exclusive stacks for system reset and machine check exception. */
 	void *nmi_emergency_sp;
 	void *mc_emergency_sp;

arch/powerpc/kernel/asm-offsets.c

···
 	OFFSET(PACAHWCPUID, paca_struct, hw_cpu_id);
 	OFFSET(PACAKEXECSTATE, paca_struct, kexec_state);
 	OFFSET(PACA_DSCR_DEFAULT, paca_struct, dscr_default);
-#ifdef CONFIG_PPC64
 	OFFSET(PACA_EXIT_SAVE_R1, paca_struct, exit_save_r1);
-#endif
 #ifdef CONFIG_PPC_BOOK3E_64
 	OFFSET(PACA_TRAP_SAVE, paca_struct, trap_save);
 #endif

arch/powerpc/platforms/powermac/feature.c

···
 		PMAC_TYPE_POWERMAC_G5,		g5_features,
 		0,
 	},
-#ifdef CONFIG_PPC64
 	{	"PowerMac7,3",			"PowerMac G5",
 		PMAC_TYPE_POWERMAC_G5,		g5_features,
 		0,
···
 		PMAC_TYPE_XSERVE_G5,		g5_features,
 		0,
 	},
-#endif /* CONFIG_PPC64 */
 #endif /* CONFIG_PPC64 */
 };
 

arch/powerpc/xmon/xmon.c

···
 			touch_nmi_watchdog();
 		} else {
 			cmd = 1;
-#ifdef CONFIG_SMP
 			if (xmon_batch)
 				cmd = batch_cmds(regs);
-#endif
 			if (!locked_down && cmd)
 				cmd = cmds(regs);
 			if (locked_down || cmd != 0) {