MMIO unmap fix

[elicn]

Highlights:

• Consolidated MMIO bookkeeping with ordinary memory to simplify its maintenance. This fixes Unmapping part of a MMIO region causes future ql.saves to crash #1137
• Fixed a minor bug in change_mapinfo

To test the fix, the repro code from the original issue has been adjusted to the most recent implementation:

from qiling import Qiling
from qiling.const import QL_ARCH, QL_OS
from qiling.os.memory import QlMmioHandler


class NullHandler(QlMmioHandler):
    def read(self, ql: Qiling, offset: int, size: int) -> int:
        return 0

    def write(self, ql: Qiling, offset: int, size: int, value: int) -> None:
        pass


ql = Qiling(code=b"\0", archtype=QL_ARCH.ARM, ostype=QL_OS.LINUX)

ql.mem.map_mmio(0, 0x2000, NullHandler())
ql.mem.unmap(0x1000, 0x1000)

ql.save(reg=False, mem=True)