Refine SPI bitbanging

Change the SPI bitbanging core to fix a subtle bug (which had no
effect so far) and to make integration of the RayeR SPIPGM and Nvidia
MCP6x/MCP7x SPI patches easier. Kill a few global variables and require
explicit initialization of bitbanging delay.

A big to Johannes Sjölund for testing an earlier version of the code as
part of the Nvidia MCP6x/MCP7x SPI bitbanging patch.

Corresponding to flashrom svn r1085.

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/flash.h b/flash.h
index 2065109..c858eba 100644
--- a/flash.h
+++ b/flash.h
@@ -133,8 +133,6 @@
 
 extern const int bitbang_spi_master_count;
 
-extern enum bitbang_spi_master bitbang_spi_master;
-
 struct bitbang_spi_master_entry {
 	void (*set_cs) (int val);
 	void (*set_sck) (int val);
@@ -533,9 +531,7 @@
 int ft2232_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);
 
 /* bitbang_spi.c */
-extern int bitbang_spi_half_period;
-extern const struct bitbang_spi_master_entry bitbang_spi_master_table[];
-int bitbang_spi_init(void);
+int bitbang_spi_init(enum bitbang_spi_master master, int halfperiod);
 int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt, const unsigned char *writearr, unsigned char *readarr);
 int bitbang_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len);
 int bitbang_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len);