i2c: cpm: Fix i2c_ram structure

the i2c_ram structure is missing the sdmatmp field mentionned in
datasheet for MPC8272 at paragraph 36.5. With this field missing, the
hardware would write past the allocated memory done through
cpm_muram_alloc for the i2c_ram structure and land in memory allocated
for the buffers descriptors corrupting the cbd_bufaddr field. Since this
field is only set during setup(), the first i2c transaction would work
and the following would send data read from an arbitrary memory
location.

Fixes: 61045dbe

 ("i2c: Add support for I2C bus on Freescale CPM1/CPM2 controllers")
Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>
Acked-by: Jochen Friedrich <jochen@scram.de>
Acked-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Wolfram Sang <wsa@kernel.org>