kernel: disable GENTLE_FAIR_SLEEPERS
fs: NOATIME and NODIRATIME by default
lib: Introduce some memory copy macros and functions

The kernel's memcpy and memmove is very inefficient. But the glibc version is
quite fast, in some cases it is 10 times faster than the kernel version. So I
introduce some memory copy macros and functions of the glibc to improve the
kernel version's performance.

The strategy of the memory functions is:
1. Copy bytes until the destination pointer is aligned.
2. Copy words in unrolled loops. If the source and destination are not aligned
   in the same way, use word memory operations, but shift and merge two read
   words before writing.
3. Copy the few remaining bytes.

Signed-off-by: Miao Xie <miaox@...fujitsu.com>
lib: Improve the performance of memcpy and memmove of the general version

The performance of memcpy and memmove of the general version is
very inefficient, this patch improves them.
cpufreq: add bacem tweak
arm: arch: enable bacem tweak