zipl/boot: Conditionally clear memory upon reipl at ccw dump end

- Instead of always clearing the memory on reipl after the ccw dump has
  been taken, check for the special OS_INFO_FLAG_REIPL_CLEAR flag in
  os_info flags entry (indicates if sysfs 'clear' attribute has been set
  on the panicked system) and trigger diag308 with a proper subcode.
- Get rid of superfluous ipib_info structure in stage2dump.c.
- Collect ipl_pbt constants in boot/ipl.h header.

Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

include/boot/ipl.h

@@ -21,10 +21,6 @@
 #define IPL_MAX_SUPPORTED_VERSION	0
 #define IPL_PARM_BLOCK_VERSION		0x1
 
-/* IPL Types */
-#define IPL_TYPE_PV			0x5
-
-
 #ifndef __ASSEMBLER__
 
 #include <stdint.h>
@@ -43,6 +39,16 @@ struct ipl_pb_hdr {
 	uint8_t  pbt;
 } __packed;
 
+/* IPL Parameter Block types */
+enum ipl_pbt {
+	IPL_PBT_FCP = 0,
+	IPL_PBT_SCP_DATA = 1,
+	IPL_PBT_CCW = 2,
+	IPL_PBT_ECKD = 3,
+	IPL_PBT_NVME = 4,
+	IPL_PBT_PV = 5,
+};
+
 /* IPL Parameter Block 0 with common fields */
 struct ipl_pb0_common {
 	uint32_t len;