powerpc: Add HAVE_PERF_USER_STACK_DUMP support

With perf regs support enabled for powerpc, in commit ed4a4ef8
("powerpc/perf: Add support for sampling interrupt register state"),
the support for obtaining perf user stack dump is already enabled. This
patch declares the support for same and also updates documentation to
mark the support for perf-regs and perf-stackdump.

Signed-off-by: Chandan Kumar <chandan.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Documentation/features/perf/perf-regs/arch-support.txt

@@ -27,7 +27,7 @@
     |       nios2: | TODO |
     |    openrisc: | TODO |
     |      parisc: | TODO |
-    |     powerpc: | TODO |
+    |     powerpc: |  ok  |
     |        s390: | TODO |
     |       score: | TODO |
     |          sh: | TODO |

Documentation/features/perf/perf-stackdump/arch-support.txt

@@ -27,7 +27,7 @@
     |       nios2: | TODO |
     |    openrisc: | TODO |
     |      parisc: | TODO |
-    |     powerpc: | TODO |
+    |     powerpc: |  ok  |
     |        s390: | TODO |
     |       score: | TODO |
     |          sh: | TODO |

arch/powerpc/Kconfig

@@ -117,6 +117,7 @@ config PPC
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
 	select HAVE_PERF_EVENTS
 	select HAVE_PERF_REGS
+	select HAVE_PERF_USER_STACK_DUMP
 	select HAVE_REGS_AND_STACK_ACCESS_API
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS && PPC_BOOK3S_64
 	select ARCH_WANT_IPC_PARSE_VERSION