all devices / spiInterface / main: added method / infra to detect flash chip with --detect -f

src/xilinx.hpp

@@ -53,6 +53,10 @@ class Xilinx: public Device, SPIInterface {
 		 */
 		uint32_t dumpRegister(const std::string reg_name);
 
+		/*!
+		 * \brief display SPI flash ID and status register
+		 */
+		bool detect_flash() override;
 		/*!
 		 * \brief protect SPI flash blocks
 		 */