marvell: uart: a3720: Implement console_a3700_core_getc

Implementation is simple, just check if there is a pending character in
RX FIFO via RXRDY bit of Status Register and if yes, read it from
UART_RX_REG register.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I226b6e336f44f5d0ca8dcb68e49a68e8f2f49708
diff --git a/include/drivers/marvell/uart/a3700_console.h b/include/drivers/marvell/uart/a3700_console.h
index 5e3ab05..e77a165 100644
--- a/include/drivers/marvell/uart/a3700_console.h
+++ b/include/drivers/marvell/uart/a3700_console.h
@@ -48,6 +48,7 @@
 
 /* Line Status Register bits */
 #define UARTLSR_TXFIFOFULL	(1 << 11)	/* Tx Fifo Full */
+#define UARTLSR_RXRDY		(1 << 4)	/* Rx Ready */
 
 /* UART Control Register bits */
 #define UART_CTRL_RXFIFO_RESET	(1 << 14)