update readme
update configs
dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs

DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad for ARM CPUs
with native support for unaligned memory accesses (v6+) when running
little-endian.
ARM: kill off arch_is_coherent

With ixp2xxx removed, there are no platforms that define arch_is_coherent,
so the last occurrences of arch_is_coherent can be removed. Any new
platform with coherent i/o should use coherent dma mapping functions.
cpufreq: Introduce new relation for freq selection

Introduce CPUFREQ_RELATION_C for frequency selection. It selects the frequency with the minimum euclidean distance to target. In case of equal distance between 2 frequencies, it will select the greater freq.