regulator: bcm590xx: Fix .enable_reg for BCM590XX_REG_VSR

Current implementation missed the case BCM590XX_REG_VSR, so
bcm590xx_get_enable_register() returns 0 when id is BCM590XX_REG_VSR.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed