tests: fix some issues when enabling coverage for qemu_x86_64
tests: fix some issues when enabling coverage for qemu_x86_64

Fix some issues in linker.ld when enabling coverage report feature
for qemu_x86_64 platform:
1. Fix the gcov record data should not be in BSS section.
2. Fix some test case crash due to lack of memory page align before
gcov rodata.

Signed-off-by: Enjia Mai <233e651694b7770d0f980a273a8e4a6f7e2a84d4@intel.com>

zephyrproject-rtos/zephyr,nashif/zephyr,galak/zephyr,Vudentz/zephyr,nashif/zephyr,Vudentz/zephyr,nashif/zephyr,finikorg/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,galak/zephyr,finikorg/zephyr,finikorg/zephyr,finikorg/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,galak/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr