i2c: omap24xx: Surround DM_FLAG_PRE_RELOC flag with OF_CONTROL check

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>

drivers/i2c/omap24xx_i2c.c

@@ -925,7 +925,9 @@ U_BOOT_DRIVER(i2c_omap) = {
 	.probe	= omap_i2c_probe,
 	.priv_auto_alloc_size = sizeof(struct omap_i2c),
 	.ops	= &omap_i2c_ops,
+#if !CONFIG_IS_ENABLED(OF_CONTROL)
 	.flags  = DM_FLAG_PRE_RELOC,
+#endif
 };
 
 #endif /* CONFIG_DM_I2C */