Revert "arm: Add ARCH_RANDOM Kconfig"

This reverts commit 38815b258c4db9b205a4ae2a1b9a69a8974be2d5.

Change-Id: I0cfa1b55acba6163223e383683426d234b20e34c
Revert "msm: implement ARCH_RANDOM"

This reverts commit 4eedfc0ac34315e55620d53ac9b01149b2983759.

Change-Id: I0711bd7e76b8cc071c437a565c25ad40c72fe63c