lib: sbi: Simplify console platform operations

Instead of having console_putc() and console_getc() callbacks in
platform operations, it will be much simpler for console driver to
directly register these operations as device to the sbi_console
implementation.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Xiang W <wxjstz@126.com>

include/sbi_utils/serial/uart8250.h

@@ -12,10 +12,6 @@
 
 #include <sbi/sbi_types.h>
 
-void uart8250_putc(char ch);
-
-int uart8250_getc(void);
-
 int uart8250_init(unsigned long base, u32 in_freq, u32 baudrate, u32 reg_shift,
 		  u32 reg_width);