drivers: flash: flash_stm32g4x: Fix STM32G4 unaligned read access

Due to source data pointer having no alignment constraint,
extra care needs to be taken when reading source data
as dword

Signed-off-by: Yonas Alizadeh <yonas.alizadeh@alfalaval.com>

drivers/flash/flash_stm32g4x.c

@@ -246,7 +246,7 @@ int flash_stm32_write_range(const struct device *dev, unsigned int offset,
 	int i, rc = 0;
 
 	for (i = 0; i < len; i += 8, offset += 8) {
-		rc = write_dword(dev, offset, ((const uint64_t *) data)[i>>3]);
+		rc = write_dword(dev, offset, UNALIGNED_GET((const uint64_t *) data + (i>>3)));
 		if (rc < 0) {
 			return rc;
 		}