powerpc/perf: Add declarations to fix sparse warnings

Sparse warns about all the init functions:
  symbol init_ppc970_pmu was not declared. Should it be static?
  symbol init_power5p_pmu was not declared. Should it be static?
  symbol init_power5_pmu was not declared. Should it be static?
  symbol init_power6_pmu was not declared. Should it be static?
  symbol init_power7_pmu was not declared. Should it be static?
  symbol init_power9_pmu was not declared. Should it be static?
  symbol init_power8_pmu was not declared. Should it be static?
  symbol init_generic_compat_pmu was not declared. Should it be static?

They're already declared in internal.h, so just make sure all the C
files include that directly or indirectly.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://lore.kernel.org/r/20200916115637.3100484-2-mpe@ellerman.id.au

arch/powerpc/perf/isa207-common.h

@@ -13,6 +13,8 @@
 #include <asm/firmware.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 #define EVENT_EBB_MASK		1ull
 #define EVENT_EBB_SHIFT		PERF_EVENT_CONFIG_EBB_SHIFT
 #define EVENT_BHRB_MASK		1ull

arch/powerpc/perf/power10-pmu.c

@@ -9,7 +9,6 @@
 #define pr_fmt(fmt)	"power10-pmu: " fmt
 
 #include "isa207-common.h"
-#include "internal.h"
 
 /*
  * Raw event encoding for Power10:

arch/powerpc/perf/power5+-pmu.c

@@ -10,6 +10,8 @@
 #include <asm/reg.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 /*
  * Bits in event code for POWER5+ (POWER5 GS) and POWER5++ (POWER5 GS DD3)
  */

arch/powerpc/perf/power5-pmu.c

@@ -10,6 +10,8 @@
 #include <asm/reg.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 /*
  * Bits in event code for POWER5 (not POWER5++)
  */

arch/powerpc/perf/power6-pmu.c

@@ -10,6 +10,8 @@
 #include <asm/reg.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 /*
  * Bits in event code for POWER6
  */

arch/powerpc/perf/power7-pmu.c

@@ -10,6 +10,8 @@
 #include <asm/reg.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 /*
  * Bits in event code for POWER7
  */

arch/powerpc/perf/ppc970-pmu.c

@@ -9,6 +9,8 @@
 #include <asm/reg.h>
 #include <asm/cputable.h>
 
+#include "internal.h"
+
 /*
  * Bits in event code for PPC970
  */