cros_ec: Use standard calls for recovery-request checking

Rather than calling directly into the sandbox SDL code, we can use the
normal U-Boot console handling for this feature. Update the code, to make
it more generic.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/misc/cros_ec_sandbox.c b/drivers/misc/cros_ec_sandbox.c
index 12cc11e..2173517 100644
--- a/drivers/misc/cros_ec_sandbox.c
+++ b/drivers/misc/cros_ec_sandbox.c
@@ -624,15 +624,19 @@
 	struct ec_state *ec = dev_get_priv(dev);
 	ulong start;
 
-	printf("Press keys for EC to detect on reset (ESC=recovery)...");
+	printf("\nPress keys for EC to detect on reset (ESC=recovery)...");
 	start = get_timer(0);
-	while (get_timer(start) < 1000)
-		;
-	putc('\n');
-	if (!sandbox_sdl_key_pressed(KEY_ESC)) {
-		ec->recovery_req = true;
-		printf("   - EC requests recovery\n");
+	while (get_timer(start) < 2000) {
+		if (tstc()) {
+			int ch = getchar();
+
+			if (ch == 0x1b) {
+				ec->recovery_req = true;
+				printf("EC requests recovery");
+			}
+		}
 	}
+	putc('\n');
 }
 
 /* Return the byte of EC switch states */