serial: bcm6858: remove driver and switch to bcm6345

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 3bcc61e..6252dd8 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -506,16 +506,10 @@
 
 config BCM6345_SERIAL
 	bool "Support for BCM6345 UART"
-	depends on DM_SERIAL && ARCH_BMIPS
+	depends on DM_SERIAL
 	help
 	  Select this to enable UART on BCM6345 SoCs.
 
-config BCM6858_SERIAL
-	bool "Support for BCM6858 UART"
-	depends on DM_SERIAL && ARCH_BCM6858
-	help
-	  Select this to enable UART on BCM6358 SoCs.
-
 config FSL_LINFLEXUART
 	bool "Freescale Linflex UART support"
 	depends on DM_SERIAL