serial: a37xx: Remove CONFIG_DEBUG_UART_SHIFT options
Armada 37xx serial driver does not use CONFIG_DEBUG_UART_SHIFT.
So do not define any bogus value for CONFIG_DEBUG_UART_SHIFT option in any
Armada 37xx defconfig file.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Stefan Roese <sr@denx.de>