display-legacy: gralloc: fix random fails of alloc_buffer for qsd8k ...

...after header update

    After the header update (Change-Id: Id2842abe5850462aa7b4c962a7dfeb4ae464475b) the
    field heap_mask is not initialized. This causes random fails of alloc_buffer.
    (ex.: Black flicker for WEB-rendering)
    Solution: Update ionalloc.cpp and ionalloc.h with the AOSP versions of
    platform/hardware/qcom/display
    per 2bf30b1072517ed92fb7f20cf5f256a8a0344024

Change-Id: I2ffbb60876bb907d3f3f2ac7aede1b17252260a4