drivers: mailbox: fix control TCS sizing

Control/hidden TCS hold specific data. Data registers 0 and 1 carry the
PDC wakeup time value. There is no third data register. Fix the TCS
sizing so we write only to the two write-enabled registers.

Change-Id: I83ea3dd843878aa6643ebb266446e00162f729db
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
2 files changed