defconfig: arm64: msm: Enable KERNEL_TEXT_RDONLY in debug config for 8937

CONFIG_DEBUG_RODATA doesn't work with FORCE_PAGES
config which we enable on debug defconfig. So
instead of that enable KERNEL_TEXT_RDONLY for
read only support along with FORCE_PAGES.

We don't need this on perf-defconfig as we don't
enable FORCE_PAGES there. So we can have
CONFIG_DEBUG_RODATA enabled on perf config.

Change-Id: I429c5a5f70e53155f19705c1489d583bc161ee24
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>