Parametrize baudrate and UART clock during console_init()

This patch adds baud rate and UART clock frequency as parameters
to the pl011 driver api console_init(). This allows each platform
to specify UART clock and baud rate according to their specific
hardware implementation.

Fixes ARM-software/tf-issues#215

Change-Id: Id13eef70a1c530e709b34dd1e6eb84db0797ced2
diff --git a/include/drivers/console.h b/include/drivers/console.h
index e285909..f144ab9 100644
--- a/include/drivers/console.h
+++ b/include/drivers/console.h
@@ -31,7 +31,8 @@
 #ifndef __CONSOLE_H__
 #define __CONSOLE_H__
 
-void console_init(unsigned long base_addr);
+int console_init(unsigned long base_addr,
+		unsigned int uart_clk, unsigned int baud_rate);
 int console_putc(int c);
 int console_getc(void);