cpufreq / governor: Fix problem with cpufreq_ondemand or cpufreq_conservative

Since commit 2aacdff entitled "cpufreq: Move common part from governors
to separate file", whenever the drivers that depend on this new file
(cpufreq_ondemand or cpufreq_conservative) are built as modules, a new
module named cpufreq_governor is created because the Makefile includes
cpufreq_governor.o twice. As drivers/cpufreq/cpufreq_governor.c contains no
MODULE directives, the resulting module has no license specified, which
results in logging of a "module license 'unspecified' taints kernel". In
addition, a number of globals are exported GPL only, and are therefore
not available. This fix establishes a new boolean configuration variable
that forces cpufreq_governor.o to be linked into the kernel whenever
either cpufreq_ondemand or cpufreq_conservative is selected.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/Kconfig

@@ -20,6 +20,9 @@ if CPU_FREQ
 config CPU_FREQ_TABLE
 	tristate
 
+config CPU_FREQ_GOV_COMMON
+	bool
+
 config CPU_FREQ_STAT
 	tristate "CPU frequency translation statistics"
 	select CPU_FREQ_TABLE
@@ -141,6 +144,7 @@ config CPU_FREQ_GOV_USERSPACE
 config CPU_FREQ_GOV_ONDEMAND
 	tristate "'ondemand' cpufreq policy governor"
 	select CPU_FREQ_TABLE
+	select CPU_FREQ_GOV_COMMON
 	help
 	  'ondemand' - This driver adds a dynamic cpufreq policy governor.
 	  The governor does a periodic polling and 
@@ -159,6 +163,7 @@ config CPU_FREQ_GOV_ONDEMAND
 config CPU_FREQ_GOV_CONSERVATIVE
 	tristate "'conservative' cpufreq governor"
 	depends on CPU_FREQ
+	select CPU_FREQ_GOV_COMMON
 	help
 	  'conservative' - this driver is rather similar to the 'ondemand'
 	  governor both in its source code and its purpose, the difference is

drivers/cpufreq/Makefile

@@ -7,8 +7,9 @@ obj-$(CONFIG_CPU_FREQ_STAT)             += cpufreq_stats.o
 obj-$(CONFIG_CPU_FREQ_GOV_PERFORMANCE)	+= cpufreq_performance.o
 obj-$(CONFIG_CPU_FREQ_GOV_POWERSAVE)	+= cpufreq_powersave.o
 obj-$(CONFIG_CPU_FREQ_GOV_USERSPACE)	+= cpufreq_userspace.o
-obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND)	+= cpufreq_ondemand.o cpufreq_governor.o
-obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE)	+= cpufreq_conservative.o cpufreq_governor.o
+obj-$(CONFIG_CPU_FREQ_GOV_ONDEMAND)	+= cpufreq_ondemand.o
+obj-$(CONFIG_CPU_FREQ_GOV_CONSERVATIVE)	+= cpufreq_conservative.o
+obj-$(CONFIG_CPU_FREQ_GOV_COMMON)		+= cpufreq_governor.o
 
 # CPUfreq cross-arch helpers
 obj-$(CONFIG_CPU_FREQ_TABLE)		+= freq_table.o