libsigrok.h: Add MQ for electric charge.

include/libsigrok/libsigrok.h

@@ -235,6 +235,8 @@ enum sr_mq {
 	SR_MQ_HARMONIC_RATIO,
 	/** Energy. */
 	SR_MQ_ENERGY,
+	/** Electric charge. */
+	SR_MQ_ELECTRIC_CHARGE,
 
 	/* Update sr_key_info_mq[] (hwdriver.c) upon changes! */
 };

src/hwdriver.c

@@ -273,6 +273,7 @@ static struct sr_key_info sr_key_info_mq[] = {
 	{SR_MQ_MASS, 0, "mass", "Mass", NULL},
 	{SR_MQ_HARMONIC_RATIO, 0, "harmonic_ratio", "Harmonic ratio", NULL},
 	{SR_MQ_ENERGY, 0, "energy", "Energy", NULL},
+	{SR_MQ_ELECTRIC_CHARGE, 0, "electric_charge", "Electric charge", NULL},
 	ALL_ZERO
 };