revert to 32-bit objd values

The size of the objd->value member was previously increased to 64-bit
to allow setting 64-bit default values. This may waste some (ROM)
memory as 64-bit values are somewhat uncommon, and the value can be
set from an application hook instead. Revert to 32-bit values.

Fix #59

soes/esc_coe.c

@@ -1121,9 +1121,8 @@ void COE_initDefaultValues (void)
       i = 0;
       do
       {
-         if (objd[i].data != NULL)
+         if (objd[i].data != NULL && objd[i].bitlength <= sizeof(objd[i].value))
          {
-            /* TODO: bitlength > 64 */
             COE_setValue (&objd[i], objd[i].value);
             DPRINT ("%04x:%02x = %x\n", SDOobjects[n].index, objd[i].subindex, objd[i].value);
          }

soes/esc_coe.h

@@ -21,7 +21,7 @@ typedef struct CC_PACKED
    uint16_t bitlength;
    uint16_t flags;
    const char *name;
-   uint64_t value;
+   uint32_t value;
    void *data;
 } _objd;
 CC_PACKED_END