memshare: Modify the qmi response buffer size

Unavailability of enough buffer is causing task starvation while
sending memory free qmi response. Modify the buffer size of the
qmi free response to prevent encoding failures and thus task
starvation.

Change-Id: I2086f6fac66465ac3dba6339d6390d5d39698404
Signed-off-by: Manoj Prabhu B <bmanoj@codeaurora.org>