i2c: i2c-bfin-twi: Always access 16 bit MMR by bfin 16 bit access Macro.

Otherwise, the compiler may optimize assemble code into 8bit access instruction
when target register is 8 bit width.
Signed-off-by: NSonic Zhang <sonic.zhang@analog.com>
Signed-off-by: NBob Liu <lliubbo@gmail.com>

arch/blackfin/include/asm/bfin_twi.h

@@ -66,9 +66,9 @@ struct bfin_twi_iface {
 
 #define DEFINE_TWI_REG(reg_name, reg) \
 static inline u16 read_##reg_name(struct bfin_twi_iface *iface) \
-	{ return iface->regs_base->reg; } \
+	{ return bfin_read16(&iface->regs_base->reg); } \
 static inline void write_##reg_name(struct bfin_twi_iface *iface, u16 v) \
-	{ iface->regs_base->reg = v; }
+	{ bfin_write16(&iface->regs_base->reg, v); }
 
 DEFINE_TWI_REG(CLKDIV, clkdiv)
 DEFINE_TWI_REG(CONTROL, control)