[ARM] 5048/2: Clean up tosa and spitz resetting

Use new reset_gpio to reset tosa and spitz PDAs.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>