flash/bluenrg-x: support programming without loader

fallback programming without loader when resources are not available
while at there refactor reused code
(wait for interrupt and command execution)

Change-Id: I2cba0f53d3470bc324f4a72614c236cebf196f64
Signed-off-by: BOCHKATI Tarek <tarek.bochkati@st.com>
Signed-off-by: HAOUES Ahmed <ahmed.haoues@st.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/8883
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/flash/nor/bluenrg-x.h

@@ -28,7 +28,12 @@
 #define FLASH_CMD_WRITE      0x33
 #define FLASH_CMD_BURSTWRITE 0xCC
 #define FLASH_INT_CMDDONE    0x01
+#define FLASH_INT_CMDSTART   0x02
 
+/* Flash Controller constants */
 #define FLASH_WORD_LEN       4
+#define FLASH_DATA_WIDTH_W   4
+#define FLASH_DATA_WIDTH     16
+
 
 #endif /* OPENOCD_FLASH_NOR_BLUENRGX_H */