gpiolib: acpi: support bias pull disable

On top of looking at PULL_UP and PULL_DOWN flags, also look at
PULL_DISABLE and set the appropriate GPIO flag. The GPIO core will then
pass down this to controllers that support it.

Change-Id: I78df1dc294ae916c1f52888e1c0b9e897042a4ed
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/312115
Tested-by: Eric FOURMONT <eric.fourmont-ext@st.com>
Reviewed-by: Eric FOURMONT <eric.fourmont-ext@st.com>
Domain-Review: Eric FOURMONT <eric.fourmont-ext@st.com>

Author: nunojsa

drivers/gpio/gpiolib-acpi.c

@@ -702,6 +702,9 @@ int acpi_gpio_update_gpiod_lookup_flags(unsigned long *lookupflags,
 	case ACPI_PIN_CONFIG_PULLDOWN:
 		*lookupflags |= GPIO_PULL_DOWN;
 		break;
+	case ACPI_PIN_CONFIG_NOPULL:
+		*lookupflags |= GPIO_PULL_DISABLE;
+		break;
 	default:
 		break;
 	}