The "read_bhrb" global symbol is only called under CONFIG_PPC64 of
arch/powerpc/perf/core-book3s.c but it is compiled for both 32 and 64 bit
anyway (and LLVM fails to link this on 32bit).
This fixes it by moving bhrb.o to obj64 targets.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220421025756.571995-1-aik@ozlabs.ru
 obj-y                          += callchain.o callchain_$(BITS).o perf_regs.o
 obj-$(CONFIG_COMPAT)           += callchain_32.o
 
-obj-$(CONFIG_PPC_PERF_CTRS)    += core-book3s.o bhrb.o
+obj-$(CONFIG_PPC_PERF_CTRS)    += core-book3s.o
 obj64-$(CONFIG_PPC_PERF_CTRS)  += ppc970-pmu.o power5-pmu.o \
                                   power5+-pmu.o power6-pmu.o power7-pmu.o \
                                   isa207-common.o power8-pmu.o power9-pmu.o \
-                                  generic-compat-pmu.o power10-pmu.o
+                                  generic-compat-pmu.o power10-pmu.o bhrb.o
 obj32-$(CONFIG_PPC_PERF_CTRS)  += mpc7450-pmu.o
 
 obj-$(CONFIG_PPC_POWERNV)      += imc-pmu.o