[SRC_C][U-BOOT] add code for correct current boot

The changes done make sure to switch correctly the current boot slot which before doesn't switch even if the slot was invalidated. Furthermore, the commit introduces the case where both the partitions used are invalidated which takes to an ERROR. Some comments useful for debugging has been removed because no longer needed. The cmd/sysdata.c has been changed due to an error of the "initialize" command which returns "Table not initialized" even if the table was initialize. This is caused by a change of the return of various functions which now return the number of bits and not just 0 and 1 like the old sysdata.

Signed-off-by: default avatarCarlo Ferriolo carlo.ferriolo@seco.com