eeprom: Add bus argument to eeprom_init()

Add bus argument to eeprom_init(), so that it can select
the I2C bus number on which the eeprom resides. Any negative
value of the $bus argument will preserve the old behavior.
This is in place so that old code does not randomly break.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: Heiko Schocher <hs@denx.de>
[trini: Wrap i2c_set_bus_num() call with CONFIG_SYS_I2C test]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/env_eeprom.c b/common/env_eeprom.c
index eea169d..72b1373 100644
--- a/common/env_eeprom.c
+++ b/common/env_eeprom.c
@@ -91,7 +91,7 @@
 	uchar rdbuf[64], flags[2];
 	int i, crc_ok[2] = {0, 0};
 
-	eeprom_init();	/* prepare for EEPROM read/write */
+	eeprom_init(-1);	/* prepare for EEPROM read/write */
 
 	off_env[0] = CONFIG_ENV_OFFSET;
 	off_env[1] = CONFIG_ENV_OFFSET_REDUND;
@@ -154,7 +154,7 @@
 	ulong crc, len, new;
 	uchar rdbuf[64];
 
-	eeprom_init();	/* prepare for EEPROM read/write */
+	eeprom_init(-1);	/* prepare for EEPROM read/write */
 
 	/* read old CRC */
 	eeprom_bus_read(CONFIG_SYS_DEF_EEPROM_ADDR,