dts_fixups: Use DT_ prefix in all defined labels not related to Kconfig

These changes were obtained by running a script  created by
Ulf Magnusson <Ulf.Magnusson@nordicsemi.no> for the following
specification:

1. Read the contents of all dts_fixup.h files in Zephyr
2. Check the left-hand side of the #define macros (i.e. the X in
   #define X Y)
3. Check if that name is also the name of a Kconfig option
   3.a If it is, then do nothing
   3.b If it is not, then replace CONFIG_ with DT_ or add DT_ if it
       has neither of these two prefixes
4. Replace the use of the changed #define in the code itself
   (.c, .h, .ld)

Additionally, some tweaks had to be added to this script to catch some
of the macros used in the code in a parameterized form, e.g.:
- CONFIG_GPIO_STM32_GPIO##__SUFFIX##_BASE_ADDRESS
- CONFIG_UART_##idx##_TX_PIN
- I2C_SBCON_##_num##_BASE_ADDR
and to prevent adding DT_ prefix to the following symbols:
- FLASH_START
- FLASH_SIZE
- SRAM_START
- SRAM_SIZE
- _ROM_ADDR
- _ROM_SIZE
- _RAM_ADDR
- _RAM_SIZE
which are surprisingly also defined in some dts_fixup.h files.

Finally, some manual corrections had to be done as well:
- name##_IRQ -> DT_##name##_IRQ in uart_stm32.c

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>

drivers/sensor/fxas21002/fxas21002.c

@@ -285,20 +285,20 @@ static const struct sensor_driver_api fxas21002_driver_api = {
 };
 
 static const struct fxas21002_config fxas21002_config = {
-	.i2c_name = CONFIG_FXAS21002_I2C_NAME,
-	.i2c_address = CONFIG_FXAS21002_I2C_ADDRESS,
+	.i2c_name = DT_FXAS21002_I2C_NAME,
+	.i2c_address = DT_FXAS21002_I2C_ADDRESS,
 	.whoami = CONFIG_FXAS21002_WHOAMI,
 	.range = CONFIG_FXAS21002_RANGE,
 	.dr = CONFIG_FXAS21002_DR,
 #ifdef CONFIG_FXAS21002_TRIGGER
-	.gpio_name = CONFIG_FXAS21002_GPIO_NAME,
-	.gpio_pin = CONFIG_FXAS21002_GPIO_PIN,
+	.gpio_name = DT_FXAS21002_GPIO_NAME,
+	.gpio_pin = DT_FXAS21002_GPIO_PIN,
 #endif
 };
 
 static struct fxas21002_data fxas21002_data;
 
-DEVICE_AND_API_INIT(fxas21002, CONFIG_FXAS21002_NAME, fxas21002_init,
+DEVICE_AND_API_INIT(fxas21002, DT_FXAS21002_NAME, fxas21002_init,
 		    &fxas21002_data, &fxas21002_config,
 		    POST_KERNEL, CONFIG_SENSOR_INIT_PRIORITY,
 		    &fxas21002_driver_api);