bankd_main: Obtain ATR of card via PC/SC API

Change-Id: Ie73806e2190e604cab96b3f632b4bbfffb7d0112
diff --git a/src/bankd.h b/src/bankd.h
index 0ca1984..6d4f675 100644
--- a/src/bankd.h
+++ b/src/bankd.h
@@ -83,6 +83,11 @@
 			} pcsc;
 		};
 	} reader;
+
+	struct {
+		uint8_t atr[MAX_ATR_SIZE];
+		unsigned int atr_len;
+	} card;
 };