lm-sensors: sensors-detect requires perl

The sensors-detect program is in fact a Perl script, so it won't run
on the target unless Perl is enabled in the configuration.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

package/lm-sensors/Config.in

@@ -44,8 +44,12 @@ config BR2_PACKAGE_LM_SENSORS_PWMCONFIG
 
 config BR2_PACKAGE_LM_SENSORS_SENSORS_DETECT
 	bool "sensors-detect"
+	depends on BR2_PACKAGE_PERL
 	help
 	  Sensors-detect is an interactive program for detecting
 	  available hardware monitoring chips.
 
+comment "sensors-detect needs perl"
+	depends on !BR2_PACKAGE_PERL
+
 endif