defconfig: sdm855: Enable early random driver

Stack canary relies on getting early random values.
However, the software random number generator is
initialized relatively late in the boot process
making the stack canary very predictable.
Enable the hardware supported random number generator
to provide entropy early in the boot process.

Change-Id: Ic2fc02e407c356bce04f41ea9d3e93b095540bb4
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>