riscv: qemu: Enable HTIF console support

Enable support for HTIF console so that we can use QEMU RISC-V U-Boot
on RISC-V emulators and ISS having it.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Reviewed-by: Rick Chen <rick@andestech.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

board/emulation/qemu-riscv/Kconfig

@@ -56,6 +56,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	imply DM_SCSI
 	imply SYS_NS16550
 	imply SIFIVE_SERIAL
+	imply HTIF_CONSOLE if 64BIT
 	imply SYSRESET
 	imply SYSRESET_CMD_POWEROFF
 	imply SYSRESET_SYSCON