[POWERPC] re-enable OProfile for iSeries, using timer interrupt

This patch removes the changes from an earlier patch that disables
oProfile for iSeries within the oProfile KConfig (submitted Feb 23,
2006).  Checks within the arch init for iSeries, still allowing profiling
for timer interrupts (using firmware_has_feature).
Signed-off-by: Kelly Daly <kelly@au.ibm.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/oprofile/Kconfig

 config PROFILING
-	depends on !PPC_ISERIES
 	bool "Profiling support (EXPERIMENTAL)"
 	help
 	  Say Y here to enable the extended profiling support mechanisms used

arch/powerpc/oprofile/common.c

@@ -22,6 +22,7 @@
 #include <asm/pmc.h>
 #include <asm/cputable.h>
 #include <asm/oprofile_impl.h>
+#include <asm/firmware.h>
 
 static struct op_powerpc_model *model;
 
@@ -130,6 +131,9 @@ int __init oprofile_arch_init(struct oprofile_operations *ops)
 	if (!cur_cpu_spec->oprofile_cpu_type)
 		return -ENODEV;
 
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		return -ENODEV;
+
 	switch (cur_cpu_spec->oprofile_type) {
 #ifdef CONFIG_PPC64
 		case PPC_OPROFILE_RS64: