Fix SD-Card initialization process

After command ACMD41 was being sent we were not waiting
for the error idle state bit being cleared, so we were
really never going out from the initialization phase.

include/sd_card.h

@@ -42,4 +42,8 @@ extern void sd_card_init(void);
 //#define CT_SDC		(CT_SD1|CT_SD2)	/* SD */
 #define CT_BLOCK	0x08		/* Block addressing */
 
+/*  SD error code bits */
+#define SD_ERR_IDLE_STATE       0x01
+#define SD_ERR_ILLEGAL_CMD      0x04
+
 #endif /* _SD_CARD_H_ */

spi/mmc.c

@@ -424,7 +424,7 @@ DSTATUS disk_initialize(uint8_t drv)
                 while (MCF_SLT_SCNT(0) - target > 0)
                 {
                     res = send_cmd(ACMD41, 1UL << 30);	/* Wait for end of initialization with ACMD41(HCS) */
-                    if (res != 0xff)
+                    if ((res & SD_ERR_IDLE_STATE) == 0)
                         break;
                 }
                 debug_printf("res = %d\r\n", res);