gpio: Remove DM_FLAG_PRE_RELOC flag in various drivers

When a driver declares DM_FLAG_PRE_RELOC flag, it wishes to be
bound before relocation. However due to a bug in the DM core,
the flag only takes effect when devices are statically declared
via U_BOOT_DEVICE(). This bug has been fixed recently by commit
"dm: core: Respect drivers with the DM_FLAG_PRE_RELOC flag in
lists_bind_fdt()", but with the fix, it has a side effect that
all existing drivers that declared DM_FLAG_PRE_RELOC flag will
be bound before relocation now. This may expose potential boot
failure on some boards due to insufficient memory during the
pre-relocation stage.

To mitigate this potential impact, the following changes are
implemented:

- Remove DM_FLAG_PRE_RELOC flag in the driver, if the driver
  only supports configuration from device tree (OF_CONTROL)
- Keep DM_FLAG_PRE_RELOC flag in the driver only if the device
  is statically declared via U_BOOT_DEVICE()
- Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check, for
  drivers that support both statically declared devices and
  configuration from device tree

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>

drivers/gpio/omap_gpio.c

@@ -372,7 +372,9 @@ U_BOOT_DRIVER(gpio_omap) = {
 	.ops	= &gpio_omap_ops,
 	.probe	= omap_gpio_probe,
 	.priv_auto_alloc_size = sizeof(struct gpio_bank),
+#if !CONFIG_IS_ENABLED(OF_CONTROL)
 	.flags = DM_FLAG_PRE_RELOC,
+#endif
 };
 
 #endif /* CONFIG_DM_GPIO */

drivers/gpio/stm32f7_gpio.c

@@ -123,6 +123,6 @@ U_BOOT_DRIVER(gpio_stm32) = {
 	.of_match = stm32_gpio_ids,
 	.probe	= gpio_stm32_probe,
 	.ops	= &gpio_stm32_ops,
-	.flags	= DM_FLAG_PRE_RELOC | DM_UC_FLAG_SEQ_ALIAS,
+	.flags	= DM_UC_FLAG_SEQ_ALIAS,
 	.priv_auto_alloc_size	= sizeof(struct stm32_gpio_priv),
 };

drivers/gpio/tegra186_gpio.c

@@ -281,5 +281,4 @@ U_BOOT_DRIVER(tegra186_gpio) = {
 	.bind = tegra186_gpio_bind,
 	.probe = tegra186_gpio_probe,
 	.ops = &tegra186_gpio_ops,
-	.flags = DM_FLAG_PRE_RELOC,
 };

drivers/gpio/tegra_gpio.c

@@ -378,5 +378,4 @@ U_BOOT_DRIVER(gpio_tegra) = {
 	.probe = gpio_tegra_probe,
 	.priv_auto_alloc_size = sizeof(struct tegra_port_info),
 	.ops	= &gpio_tegra_ops,
-	.flags	= DM_FLAG_PRE_RELOC,
 };