The size of buffer currently used to store the FDT passed from U-Boot as
a platform parameter is not large enough to store some RK3399 device
trees. The largest RK3399 device tree currently in U-Boot (for the
Pinebook Pro) is about 70KB in size when passed to TF-A, so increase the
buffer size to 128K which gives some headroom for possibly larger FDTs
in future.

Signed-off-by: Hugh Cole-Baker <sigmaris@gmail.com>
Change-Id: I414caf20683cd47c02ee470dfa988544f3809919