Use BOARD_EEPROM_WP_CTRL signal to control EEPROM WP signal if defined

Erases and write operations will use the BOARD_EEPROM_WP_CTRL
  macro to remove the Write protection and restore it.

src/systemcmds/mtd/24xxxx_mtd.c

@@ -203,6 +203,8 @@ static int at24c_eraseall(FAR struct at24c_dev_s *priv)
 
 	memset(&buf[2], 0xff, priv->pagesize);
 
+	BOARD_EEPROM_WP_CTRL(false);
+
 	for (startblock = 0; startblock < priv->npages; startblock++) {
 		uint16_t offset = startblock * priv->pagesize;
 		buf[1] = offset & 0xff;
@@ -214,6 +216,8 @@ static int at24c_eraseall(FAR struct at24c_dev_s *priv)
 		}
 	}
 
+	BOARD_EEPROM_WP_CTRL(true);
+
 	return OK;
 }
 
@@ -389,6 +393,8 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t
 
 	finfo("startblock: %08lx nblocks: %d\n", (long)startblock, (int)nblocks);
 
+	BOARD_EEPROM_WP_CTRL(false);
+
 	while (blocksleft-- > 0) {
 		uint16_t offset = startblock * priv->pagesize;
 		unsigned tries = CONFIG_AT24XX_WRITE_TIMEOUT_MS;
@@ -415,6 +421,7 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t
 			 */
 			if (--tries == 0) {
 				perf_count(priv->perf_errors);
+				BOARD_EEPROM_WP_CTRL(true);
 				return ERROR;
 			}
 		}
@@ -423,6 +430,8 @@ static ssize_t at24c_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t
 		buffer += priv->pagesize;
 	}
 
+	BOARD_EEPROM_WP_CTRL(true);
+
 #if CONFIG_AT24XX_MTD_BLOCKSIZE > AT24XX_PAGESIZE
 	return nblocks / (CONFIG_AT24XX_MTD_BLOCKSIZE / AT24XX_PAGESIZE);
 #else
@@ -565,6 +574,8 @@ FAR struct mtd_dev_s *at24c_initialize(FAR struct i2c_master_s *dev)
 		}
 	};
 
+	BOARD_EEPROM_WP_CTRL(true);
+
 	perf_begin(priv->perf_transfers);
 	int ret = I2C_TRANSFER(priv->dev, &msgv[0], 2);
 	perf_end(priv->perf_transfers);