Kconfig: arm64: Update dependencies for CONFIG_FORCE_PAGES

Currently we don't support having both CONFIG_DEBUG_RODATA
and CONFIG_FORCE_PAGES enabled at the same time.
Update the dependencies for CONFIG_FORCE_PAGES to enforce
this.

If there is a need for read only support with
CONFIG_FORCE_PAGES enabled then enable
CONFIG_KERNEL_TEXT_RDONLY instead of CONFIG_DEBUG_RODATA.

Change-Id: I9ee1732ed0673edc7272d32469d08133fba9637f
Signed-off-by: Liam Mark <lmark@codeaurora.org>