Blackfin arch: Fix BUG - Kernel does not link when CONFIG_CPU_FREQ_STAT=m

to reproduce:
$ make BF537-STAMP_defconfig
$ make menuconfig
  CPU Frequency scaling  --->
    [*] CPU Frequency scaling
    <M>   CPU frequency translation statistics
$ make

arch/blackfin/mach-common/built-in.o: In function `bfin_target':
arch/blackfin/mach-common/cpufreq.c:(.text+0xf1e): undefined reference to
`cpufreq_frequency_table_target'
arch/blackfin/mach-common/built-in.o: In function `bfin_verify_speed':
arch/blackfin/mach-common/cpufreq.c:(.text+0x1056): undefined reference to
`cpufreq_frequency_table_verify'
arch/blackfin/mach-common/built-in.o: In function `__bfin_cpu_init':
arch/blackfin/mach-common/cpufreq.c:(.init.text+0x554): undefined reference to
`cpufreq_frequency_table_get_attr'
arch/blackfin/mach-common/cpufreq.c:(.init.text+0x56a): undefined reference to
`cpufreq_frequency_table_cpuinfo'
arch/blackfin/mach-common/built-in.o: In function `sys_call_table':
(.data+0x83c): undefined reference to
`cpufreq_freq_attr_scaling_available_freqs'
make: *** [.tmp_vmlinux1] Error 1

Blackfin wants CPU_FREQ_TABLE
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/Kconfig

@@ -1102,6 +1102,12 @@ menu "CPU Frequency scaling"
 
 source "drivers/cpufreq/Kconfig"
 
+config BFIN_CPU_FREQ
+	bool
+	depends on CPU_FREQ
+	select CPU_FREQ_TABLE
+	default y
+
 config CPU_VOLTAGE
 	bool "CPU Voltage scaling"
 	depends on EXPERIMENTAL