arm: mvebu: armada-3720: remove unused config option

The config option CONFIG_DEBUG_UART_CLOCK is not used by Armada 3720's
serial driver (it wasn't even before the recent update of that driver).

Even if it was used, the value was incorrect (the frequency of the clock
is 25 MHz, not 25.8048 MHz).

Remove it from config files and set the default value to 0.
Signed-off-by: NMarek Behún <marek.behun@nic.cz>
Cc: Stefan Roese <sr@denx.de>
Cc: Pali Rohár <pali@kernel.org>
Reviewed-by: NPali Rohár <pali@kernel.org>
Reviewed-by: NStefan Roese <sr@denx.de>

configs/mvebu_db-88f3720_defconfig

@@ -11,7 +11,6 @@ CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_DM_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="armada-3720-db"
 CONFIG_DEBUG_UART_BASE=0xd0012000
-CONFIG_DEBUG_UART_CLOCK=25804800
 CONFIG_DEBUG_UART=y
 CONFIG_AHCI=y
 CONFIG_DISTRO_DEFAULTS=y

configs/mvebu_espressobin-88f3720_defconfig

@@ -11,7 +11,6 @@ CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_DM_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="armada-3720-espressobin"
 CONFIG_DEBUG_UART_BASE=0xd0012000
-CONFIG_DEBUG_UART_CLOCK=25804800
 CONFIG_DEBUG_UART=y
 CONFIG_AHCI=y
 CONFIG_DISTRO_DEFAULTS=y

configs/turris_mox_defconfig

@@ -11,7 +11,6 @@ CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_DM_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="armada-3720-turris-mox"
 CONFIG_DEBUG_UART_BASE=0xd0012000
-CONFIG_DEBUG_UART_CLOCK=25804800
 CONFIG_DEBUG_UART=y
 CONFIG_OF_BOARD_FIXUP=y
 CONFIG_DISTRO_DEFAULTS=y

configs/uDPU_defconfig

@@ -10,7 +10,6 @@ CONFIG_ENV_SECT_SIZE=0x10000
 CONFIG_DM_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="armada-3720-uDPU"
 CONFIG_DEBUG_UART_BASE=0xd0012000
-CONFIG_DEBUG_UART_CLOCK=25804800
 CONFIG_DEBUG_UART=y
 CONFIG_AHCI=y
 CONFIG_DISTRO_DEFAULTS=y

drivers/serial/Kconfig

@@ -443,6 +443,7 @@ config DEBUG_UART_CLOCK
 	int "UART input clock"
 	depends on DEBUG_UART
 	default 0 if DEBUG_UART_SANDBOX
+	default 0 if DEBUG_MVEBU_A3700_UART
 	help
 	  The UART input clock determines the speed of the internal UART
 	  circuitry. The baud rate is derived from this by dividing the input