Introduce a type "chipaddr" to abstract the offsets within flash regions

Use chipaddr instead of volatile uint8_t * because when we access chips
in external flashers, they are not accessed via pointers at all.

Benefits: This allows us to differentiate between volatile machine
memory accesses and flash chip accesses. It also enforces usage
of chip_{read,write}[bwl] to access flash chips, so nobody will
unintentionally use pointers to access chips anymore. Some unneeded
casts are removed as well. Grepping for chip operations and machine
memory operations doesn't yield any false positives anymore.

Compile tested on 32 bit and 64 bit Linux.

Corresponding to flashrom svn r519.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Uwe Hermann <uwe@hermann-uwe.de>
diff --git a/sst_fwhub.c b/sst_fwhub.c
index 3b74a95..6abff0c 100644
--- a/sst_fwhub.c
+++ b/sst_fwhub.c
@@ -37,7 +37,7 @@
 
 int check_sst_fwhub_block_lock(struct flashchip *flash, int offset)
 {
-	volatile uint8_t *registers = flash->virtual_registers;
+	chipaddr registers = flash->virtual_registers;
 	uint8_t blockstatus;
 
 	blockstatus = chip_readb(registers + offset + 2);
@@ -63,7 +63,7 @@
 
 int clear_sst_fwhub_block_lock(struct flashchip *flash, int offset)
 {
-	volatile uint8_t *registers = flash->virtual_registers;
+	chipaddr registers = flash->virtual_registers;
 	uint8_t blockstatus;
 
 	blockstatus = check_sst_fwhub_block_lock(flash, offset);
@@ -115,7 +115,7 @@
 {
 	int i;
 	unsigned int total_size = flash->total_size * 1024;
-	volatile uint8_t *bios = flash->virtual_memory;
+	chipaddr bios = flash->virtual_memory;
 
 	for (i = 0; i < total_size; i += flash->page_size)
 		erase_sst_fwhub_block(flash, i);
@@ -136,7 +136,7 @@
 	int i;
 	int total_size = flash->total_size * 1024;
 	int page_size = flash->page_size;
-	volatile uint8_t *bios = flash->virtual_memory;
+	chipaddr bios = flash->virtual_memory;
 	uint8_t blockstatus;
 
 	// FIXME: We want block wide erase instead of ironing the whole chip