* introduces central memory map for core/kernel
* on 32-bit platforms the kernel/core starts at 0x80000000
* on 64-bit platforms the kernel/core starts at 0xffffffc000000000
* mark kernel/core mappings as global ones (tagged TLB)
* move the exception vector to begin of core's binary,
thereby bootstrap knows from where to map it appropriately
* do not map boot modules into core anymore
* constrain core's virtual heap memory area
* differentiate in between user's and core's main thread's UTCB,
which now resides inside the kernel segment
Ref #2091
This commit moves the headers residing in `repos/base/include/spec/*/drivers`
to `repos/base/include/drivers/defs` or repos/base/include/drivers/uart`
respectively. The first one contains definitions about board-specific MMIO
iand RAM addresses, or IRQ lines. While the latter contains device driver
code for UART devices. Those definitions are used by driver implementations
in `repos/base-hw`, `repos/os`, and `repos/dde-linux`, which now need to
include them more explicitely.
This work is a step in the direction of reducing 'SPEC' identifiers overall.
Ref #2403
