lib: arm/arm64: Remove unnecessary dcache maintenance operations

On ARMv7 with multiprocessing extensions (which are mandated by the
virtualization extensions [1]), and on ARMv8, translation table walks are
coherent [2, 3], which means that no dcache maintenance operations are
required when changing the tables. Remove the maintenance operations so
that we do only the minimum required to ensure correctness.

Translation table walks are coherent if the memory where the tables
themselves reside have the same shareability and cacheability attributes
as the translation table walks. For ARMv8, this is already the case, and
it is only a matter of removing the cache operations.

However, for ARMv7, translation table walks were being configured as
Non-shareable (TTBCR.SH0 = 0b00) and Non-cacheable
(TTBCR.{I,O}RGN0 = 0b00). Fix that by marking them as Inner Shareable,
Normal memory, Inner and Outer Write-Back Write-Allocate Cacheable.

Because translation table walks are now coherent on arm, replace the
TLBIMVAA operation with TLBIMVAAIS in flush_tlb_page, which acts on the
Inner Shareable domain instead of being private to the PE.

The functions that update the translation table are called when the MMU
is off, or to modify permissions, in the case of the cache test, so
break-before-make is not necessary.

[1] ARM DDI 0406C.d, section B1.7
[2] ARM DDI 0406C.d, section B3.3.1
[3] ARM DDI 0487E.a, section D13.2.72
[4] ARM DDI 0487E.a, section K11.5.3

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Andrew Jones <drjones@redhat.com>