ext qmsi: Fix broken built-in qmsi build

Update the built-in QMSI build to add qm_flash.c into the default
build due to that the clk.c from QMSI 1.1.0 added a new dependency
on qm_flash file.

(https://gerrit.zephyrproject.org/r/#/c/4000/3/ext/hal/qmsi/drivers/clk.c

)

Jira: ZEP-703

Change-Id: I9f64e308cec21477a9b96183dec9ecca37ead373
Signed-off-by: Kuo-Lang Tseng <kuo-lang.tseng@intel.com>