Nokia RX-51: Convert to CONFIG_DM_SERIAL

For CONFIG_DM_SERIAL it is required to increase CONFIG_SYS_MALLOC_F_LEN as
default value is not enough for memory hungry CONFIG_DM_SERIAL code.

Signed-off-by: Pali Rohár <pali@kernel.org>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>

board/nokia/rx51/rx51.c

@@ -32,6 +32,7 @@
 #include <i2c.h>
 #include <video.h>
 #include <keyboard.h>
+#include <ns16550.h>
 #include <asm/global_data.h>
 #include <asm/io.h>
 #include <asm/setup.h>
@@ -788,3 +789,14 @@ U_BOOT_DRVINFOS(rx51_video) = {
 U_BOOT_DRVINFOS(rx51_kp) = {
 	{ "rx51_kp" },
 };
+
+static const struct ns16550_plat rx51_serial = {
+	.base = CONFIG_SYS_NS16550_COM3,
+	.reg_shift = 2,
+	.clock = CONFIG_SYS_NS16550_CLK,
+	.fcr = UART_FCR_DEFVAL,
+};
+
+U_BOOT_DRVINFOS(rx51_uart) = {
+	{ "omap_serial", &rx51_serial },
+};