bsps/xqspipsu: Add SFDP config space read ability

This adds a function to allow reading of the SFDP configuration space
that describes attributes of NOR flash chips.

bsps/include/dev/spi/xqspipsu-flash-helper.h

@@ -170,3 +170,23 @@ u32 QspiPsu_NOR_Get_Sector_Size(XQspiPsu *QspiPsuPtr);
  *
  ******************************************************************************/
 int QspiPsu_NOR_RDID(XQspiPsu *QspiPsuPtr, u8 *ReadBfrPtr, u32 ReadLen);
+
+/*****************************************************************************/
+/**
+ *
+ * This function performs a read of the SFDP configuration space.
+ *
+ * @param	QspiPsuPtr is a pointer to the QSPIPSU driver component to use.
+ * @param	ReadBfrPtr is a pointer to a buffer to be filled with
+ * 		configuration data.
+ * @param	ReadLen is the total length of the configuration space to read.
+ *
+ * @return	XST_SUCCESS if successful, else XST_FAILURE.
+ *
+ ******************************************************************************/
+int QspiPsu_NOR_RDSFDP(
+  XQspiPsu *QspiPsuPtr,
+  u32 Address,
+  u32 ByteCount,
+  u8 **ReadBfrPtr
+);

bsps/include/dev/spi/xqspipsu_flash_config.h

@@ -64,6 +64,7 @@ extern "C" {
 #define BULK_ERASE_CMD		0xC7
 #define	SEC_ERASE_CMD		0xD8
 #define READ_ID			0x9F
+#define READ_SFDP		0x5A
 #define READ_CONFIG_CMD		0x35
 #define WRITE_CONFIG_CMD	0x01
 #define ENTER_4B_ADDR_MODE	0xB7