gpio: sandbox: Rename GPIO dir_flags to flags

Adjust the terminology in this driver to reflect that fact that all flags
are handled, not just direction flags.

Create a new access function to get the full GPIO state, not just the
direction flags. Drop the static invalid_dir_flags since we can rely on a
segfault if something is wrong.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/arch/sandbox/include/asm/gpio.h b/arch/sandbox/include/asm/gpio.h
index df4ba4f..20d7829 100644
--- a/arch/sandbox/include/asm/gpio.h
+++ b/arch/sandbox/include/asm/gpio.h
@@ -69,17 +69,17 @@
  * @param offset	GPIO offset within bank
  * @return dir_flags: bitfield accesses by GPIOD_ defines
  */
-ulong sandbox_gpio_get_dir_flags(struct udevice *dev, unsigned int offset);
+ulong sandbox_gpio_get_flags(struct udevice *dev, unsigned int offset);
 
 /**
  * Set the simulated flags of a GPIO (used only in sandbox test code)
  *
  * @param dev		device to use
  * @param offset	GPIO offset within bank
- * @param flags		dir_flags: bitfield accesses by GPIOD_ defines
+ * @param flags		bitfield accesses by GPIOD_ defines
  * @return -1 on error, 0 if ok
  */
-int sandbox_gpio_set_dir_flags(struct udevice *dev, unsigned int offset,
-			       ulong flags);
+int sandbox_gpio_set_flags(struct udevice *dev, unsigned int offset,
+			   ulong flags);
 
 #endif