drivers/mtd/at25ee: Multi-device SPI bus support

Adds a device ID to at25ee_initialize, which is stored in the
at25ee_dev_s structure. This ID is used when calling SPI_SELECT.

The implementation is based on the handling of the chip select in
mtd/ramtron.c

This change is NOT backward compatible: the function signature has changed

Signed-off-by: Antoine Juckler <6445757+ajuckler@users.noreply.github.com>

include/nuttx/mtd/mtd.h

@@ -418,7 +418,7 @@ FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_master_s *dev);
 #endif
 
 /****************************************************************************
- * Name: at25xx_initialize
+ * Name: at25ee_initialize
  *
  * Description:
  *   Create an initialized MTD device instance for an AT25 SPI EEPROM
@@ -428,6 +428,7 @@ FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_master_s *dev);
  *
  * Input Parameters:
  *   dev        - a reference to the spi device structure
+ *   spi_devid  - SPI device ID to manage CS lines in board
  *   devtype    - device type, from include/nuttx/eeprom/spi_xx25xx.h
  *   readonly   - sets block driver to be readonly
  *
@@ -437,7 +438,8 @@ FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_master_s *dev);
  ****************************************************************************/
 
 FAR struct mtd_dev_s *at25ee_initialize(FAR struct spi_dev_s *dev,
-                                        int devtype, int readonly);
+                                        uint16_t spi_devid, int devtype,
+                                        int readonly);
 
 /****************************************************************************
  * Name: at24c_uninitialize