ad9361: fix FORCE_VCO_TUNE_ENABLE typo

The author used FORCE_VCO_TUNE instead of FORCE_VCO_TUNE_ENABLE.

FORCE_VCO_TUNE is the 8th (MSB) of the VCO capacitor tune word.
FORCE_VCO_TUNE_ENABLE is the bit that forces or not the usage
of the VCO capacitor tune word.

Signed-off-by: Darius Berghe <darius.berghe@analog.com>
(cherry picked from commit f381142)

drivers/iio/adc/ad9361.c

@@ -4646,9 +4646,9 @@ static int ad9361_fastlock_prepare(struct ad9361_rf_phy *phy, bool tx,
 
 		/* Workaround: Exiting Fastlock Mode */
 		ad9361_spi_writef(phy->spi, REG_RX_FORCE_ALC + offs, FORCE_ALC_ENABLE, 1);
-		ad9361_spi_writef(phy->spi, REG_RX_FORCE_VCO_TUNE_1 + offs, FORCE_VCO_TUNE, 1);
+		ad9361_spi_writef(phy->spi, REG_RX_FORCE_VCO_TUNE_1 + offs, FORCE_VCO_TUNE_ENABLE, 1);
 		ad9361_spi_writef(phy->spi, REG_RX_FORCE_ALC + offs, FORCE_ALC_ENABLE, 0);
-		ad9361_spi_writef(phy->spi, REG_RX_FORCE_VCO_TUNE_1 + offs, FORCE_VCO_TUNE, 0);
+		ad9361_spi_writef(phy->spi, REG_RX_FORCE_VCO_TUNE_1 + offs, FORCE_VCO_TUNE_ENABLE, 0);
 
 		ad9361_trx_vco_cal_control(phy, tx, true);
 		ad9361_spi_writef(phy->spi, REG_ENSM_CONFIG_2, ready_mask, 0);