MTK_TIMER is selected by ARCH_MEDIATEK. The commit enables
it in order to not alter the core when we enable
CONFIG_ARCH_MEDIATEK in vendor fragment.
It is also not directly settable due to visibility
condition "if COMPILE_TEST" not met thus selecting
it as a hidden config.
The GKI_HIDDEN_MTK_CONFIGS is enabled if ARM64 since
it is only applicable to Mediatek devices.
Bug: 432487220
Bug: 532940853
Bug: 545953895
Change-Id: Iac562e539063a59f3988e87a151251eb7554f964
Signed-off-by: Zyta Szpak <zyta@google.com>
(cherry picked from commit a79d348482)
(cherry picked from commit bcb75c47c8566960be30d9c3cf14f8b5bbf4d49a)