mfd: da9053: Addition of extra registers for GPIOs 8-13

Definitions for GPIO registers 8, 9, 10, 11, 12 and 13 are added into
the register header file.

- DA9052_GPIO_8_9_REG    25
- DA9052_GPIO_10_11_REG  26
- DA9052_GPIO_12_13_REG  27

A modification is also made to the MFD core code to define these registers
as readable and writable. The functions for da9052_reg_readable() and
da9052_reg_writeable() have had their case statements altered to include
these new registers.

Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/da9052-core.c b/drivers/mfd/da9052-core.c
index 46e3840..c0bf68a 100644
--- a/drivers/mfd/da9052-core.c
+++ b/drivers/mfd/da9052-core.c
@@ -51,6 +51,9 @@
 	case DA9052_GPIO_2_3_REG:
 	case DA9052_GPIO_4_5_REG:
 	case DA9052_GPIO_6_7_REG:
+	case DA9052_GPIO_8_9_REG:
+	case DA9052_GPIO_10_11_REG:
+	case DA9052_GPIO_12_13_REG:
 	case DA9052_GPIO_14_15_REG:
 	case DA9052_ID_0_1_REG:
 	case DA9052_ID_2_3_REG:
@@ -178,6 +181,9 @@
 	case DA9052_GPIO_2_3_REG:
 	case DA9052_GPIO_4_5_REG:
 	case DA9052_GPIO_6_7_REG:
+	case DA9052_GPIO_8_9_REG:
+	case DA9052_GPIO_10_11_REG:
+	case DA9052_GPIO_12_13_REG:
 	case DA9052_GPIO_14_15_REG:
 	case DA9052_ID_0_1_REG:
 	case DA9052_ID_2_3_REG: