MLK-20207-1: input: synaptics_dsx_i2c: fix coverity wrong sizeof argument issue

MLK-20207-1: input: synaptics_dsx_i2c: fix coverity wrong sizeof argument issue

CID 3869704: Wrong sizeof argument (SIZEOF_MISMATCH)
suspicious_sizeof: Passing argument f1a->button_control.txrx_map of
type unsigned char * and argument 8 /* sizeof (f1a->button_control.txrx_map) */
to function synaptics_rmi4_i2c_read is suspicious.

Passing argument should be sizeof(unsigned char) rather than
sizeof(unsigned char *).

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
(cherry picked from commit 4583a0bc1ff6684e1d850eb50308ad8ae2fea627)
Signed-off-by: Arulpandiyan Vadivel <arulpandiyan_vadivel@mentor.com>