net: phy: Remove unnecessary indentation in the comments of phy_device

Fix warning as:

linux-next/Documentation/networking/kapi:122: ./include/linux/phy.h:543: WARNING: Unexpected indentation.
linux-next/Documentation/networking/kapi:122: ./include/linux/phy.h:544: WARNING: Block quote ends without a blank line; unexpected unindent.
linux-next/Documentation/networking/kapi:122: ./include/linux/phy.h:546: WARNING: Unexpected indentation.
Suggested-by: Akira Yokosawa <akiyks@gmail.com>
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/linux/phy.h

@@ -538,10 +538,11 @@ struct macsec_ops;
  * @mac_managed_pm: Set true if MAC driver takes of suspending/resuming PHY
  * @state: State of the PHY for management purposes
  * @dev_flags: Device-specific flags used by the PHY driver.
- *		Bits [15:0] are free to use by the PHY driver to communicate
+ *
+ *      - Bits [15:0] are free to use by the PHY driver to communicate
  *        driver specific behavior.
- *		Bits [23:16] are currently reserved for future use.
- *		Bits [31:24] are reserved for defining generic
+ *      - Bits [23:16] are currently reserved for future use.
+ *      - Bits [31:24] are reserved for defining generic
  *        PHY driver behavior.
  * @irq: IRQ number of the PHY's interrupt (-1 if none)
  * @phy_timer: The timer for handling the state machine