linux-next: build failure after merge of the i2c tree

[Stephen Rothwell]

Hi Wolfram,

After merging the i2c tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

drivers/i2c/busses/i2c-zx2967.c: In function 'zx2967_i2c_writesb':
drivers/i2c/busses/i2c-zx2967.c:87:2: error: implicit declaration of function 
'writesb' [-Werror=implicit-function-declaration]
  writesb(i2c->reg_base + reg, data, len);
  ^
drivers/i2c/busses/i2c-zx2967.c: In function 'zx2967_i2c_readsb':
drivers/i2c/busses/i2c-zx2967.c:93:2: error: implicit declaration of function 
'readsb' [-Werror=implicit-function-declaration]
  readsb(i2c->reg_base + reg, data, len);
  ^

Caused by commit

  9615a01f71ca ("i2c: zx2967: add i2c controller driver for ZTE's zx2967 
family")

Forgotten some include file, presumably.  And COMPILE_TEST may have
been a bit hopeful :-)

I have used the i2c tree from next-20170623 for today.

-- 
Cheers,
Stephen Rothwell