accel/ivpu: Move MMU register definitions to ivpu_mmu.c

MMU registers are not platform specific so they should be defined
separate to platform regs.

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230901094957.168898-12-stanislaw.gruszka@linux.intel.com