board_f: Remove dead code from init_func_i2c

Since commit 69153988 ("i2c: Finish dropping use of CONFIG_I2C_HARD")
init_func_i2c is wrapped only by "#if defined(CONFIG_SYS_I2C)". Because
of this, the second ifdef within becomes pointless:

 #if defined(CONFIG_SYS_I2C)
 static int init_func_i2c(void)
 <snip>
     #ifdef CONFIG_SYS_I2C
         ...
     #else
         ...
     #endif
 <snip>
 }
 #endif

Remove the dead #else preprocessor code.

Fixes: 69153988 ("i2c: Finish dropping use of CONFIG_I2C_HARD")
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>