[PATCH 2/4] arm: mm: support ARCH_MMAP_RND_BITS.

From: dcashman arm: arch_mmap_rnd() uses a hard-code value of 8 to generate the random offset for the mmap base address. This value represents a compromise between increased ASLR effectiveness and avoiding address-space fragmentation. Replace it with a Kconfig option, which is sensibly bounded,

[PATCH 2/4] arm: mm: support ARCH_MMAP_RND_BITS.

From: dcashman arm: arch_mmap_rnd() uses a hard-code value of 8 to generate the random offset for the mmap base address. This value represents a compromise between increased ASLR effectiveness and avoiding address-space fragmentation. Replace it with a Kconfig option, which