IAR compiler compatibility break in image.h

[Karambite]

#ifndef __packed
#define __packed __attribute__((__packed__))
#endif

This is a compatibility break with IAR compiler. __packed is already a keyword that eliminates padding between members. This is not a definition, meaning it will always fall under the #ifndef. Any additions that uses __packed will be replaced by the definition given. Since this macro is targeted for GCC compiler, this should either be wrapped around a macro that checks if the compiler being used is GCC.

[nordicjm]

Please submit a PR with the fix

[Karambite]

PR has been created

[Karambite]

New PR is #2149