Kill global variables, constants and functions if local scope suffices

Constify variables where possible.
Initialize programmer-related variables explicitly in programmer_init to
allow running programmer_init from a clean state after
programmer_shutdown.
Prohibit registering programmer shutdown functions before init or after
shutdown.
Kill some dead code.
Rename global variables with namespace-polluting names.
Use a previously unused locking helper function in sst49lfxxxc.c.

This is needed for libflashrom.

Effects on the binary size of flashrom are minimal (300 bytes
shrinkage), but the data section shrinks by 4384 bytes, and that's a
good thing if flashrom is operating in constrained envionments.

Corresponding to flashrom svn r1068.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Michael Karcher <flashrom@mkarcher.dialup.fu-berlin.de>
diff --git a/board_enable.c b/board_enable.c
index f9f96cb..44267b0 100644
--- a/board_enable.c
+++ b/board_enable.c
@@ -1577,7 +1577,7 @@
  */
 
 /* Please keep this list alphabetically ordered by vendor/board name. */
-struct board_pciid_enable board_pciid_enables[] = {
+const struct board_pciid_enable board_pciid_enables[] = {
 
 	/* first pci-id set [4],          second pci-id set [4],          dmi identifier coreboot id [2],             vendor name    board name       max_rom_...  OK? flash enable */
 #if defined(__i386__) || defined(__x86_64__)
@@ -1661,11 +1661,11 @@
  * Match boards on coreboot table gathered vendor and part name.
  * Require main PCI IDs to match too as extra safety.
  */
-static struct board_pciid_enable *board_match_coreboot_name(const char *vendor,
+static const struct board_pciid_enable *board_match_coreboot_name(const char *vendor,
 							    const char *part)
 {
-	struct board_pciid_enable *board = board_pciid_enables;
-	struct board_pciid_enable *partmatch = NULL;
+	const struct board_pciid_enable *board = board_pciid_enables;
+	const struct board_pciid_enable *partmatch = NULL;
 
 	for (; board->vendor_name; board++) {
 		if (vendor && (!board->lb_vendor
@@ -1714,9 +1714,9 @@
  * Match boards on PCI IDs and subsystem IDs.
  * Second set of IDs can be main only or missing completely.
  */
-static struct board_pciid_enable *board_match_pci_card_ids(void)
+const static struct board_pciid_enable *board_match_pci_card_ids(void)
 {
-	struct board_pciid_enable *board = board_pciid_enables;
+	const struct board_pciid_enable *board = board_pciid_enables;
 
 	for (; board->vendor_name; board++) {
 		if ((!board->first_card_vendor || !board->first_card_device) &&
@@ -1762,7 +1762,7 @@
 
 int board_flash_enable(const char *vendor, const char *part)
 {
-	struct board_pciid_enable *board = NULL;
+	const struct board_pciid_enable *board = NULL;
 	int ret = 0;
 
 	if (part)