gpio/pca953x: Update GPIO_PCA953X Kconfig entry to include more supported devices

The Kconfig description and help text doesn't list all of the devices
supported by this driver.  This patch adds the PCA957x devices.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/gpio/Kconfig

@@ -243,7 +243,7 @@ config GPIO_MC9S08DZ60
 	  Select this to enable the MC9S08DZ60 GPIO driver
 
 config GPIO_PCA953X
-	tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports"
+	tristate "PCA953x, PCA955x, PCA957x, TCA64xx, and MAX7310 I/O ports"
 	depends on I2C
 	help
 	  Say yes here to provide access to several register-oriented
@@ -252,10 +252,11 @@ config GPIO_PCA953X
 
 	  4 bits:	pca9536, pca9537
 
-	  8 bits:	max7310, pca9534, pca9538, pca9554, pca9557,
-	  		tca6408
+	  8 bits:	max7310, max7315, pca6107, pca9534, pca9538, pca9554,
+			pca9556, pca9557, pca9574, tca6408
 
-	  16 bits:	pca9535, pca9539, pca9555, tca6416
+	  16 bits:	max7312, max7313, pca9535, pca9539, pca9555, pca9575,
+			tca6416
 
 config GPIO_PCA953X_IRQ
 	bool "Interrupt controller support for PCA953x"