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/shakti-uart.h

@@ -9,10 +9,6 @@
 
 #include <sbi/sbi_types.h>
 
-void shakti_uart_putc(char ch);
-
-int shakti_uart_getc(void);
-
 int shakti_uart_init(unsigned long base, u32 in_freq, u32 baudrate);
 
 #endif