Changes

ccid_host: fix read_timeout defined but not used

Comment out the read_timeout fuction, as it is only used in already
commented out code. Fix for:

cuart_driver_tty.c:90:12: warning: 'read_timeout' defined but not used [-Wunused-function]
   90 | static int read_timeout(int fd, uint8_t *out, size_t len, unsigned long timeout_ms)

Change-Id: I49fc59ebaa4abc3e9b8838e1b427f4455acdb390