core: assert that paging can be initialized
core: assert that paging can be initialized

Adds an assert in kernel/kern.ld.S that there's enough free pages to
initialize paging when CFG_WITH_PAGER = y.

Signed-off-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org>
Tested-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org> (FVP)
Reviewed-by: Pascal Brand <0b55292d2562685bad4ce52d64f802e8f1cd299e@linaro.org>

chshxi1989/optee_os,cedric-chaumont-st-dev/optee_os,cedric-chaumont-st-dev/optee_os,BreezeWu/optee_os,pascal-brand-st-dev/optee_os,matt2048/optee_os,chshxi1989/optee_os,cedric-chaumont-st-dev/optee_os,pascal-brand-st-dev/optee_os,matt2048/optee_os,chshxi1989/optee_os,BreezeWu/optee_os,Microsoft/optee_os,Microsoft/optee_os,chshxi1989/optee_os,Microsoft/optee_os,BreezeWu/optee_os,cedric-chaumont-st-dev/optee_os,Microsoft/optee_os,matt2048/optee_os,BreezeWu/optee_os,matt2048/optee_os,pascal-brand-st-dev/optee_os,chshxi1989/optee_os,pascal-brand-st-dev/optee_os,BreezeWu/optee_os,Microsoft/optee_os,pascal-brand-st-dev/optee_os