MA-14916 fix build and function issues of fastboot for Android

MA-14916 fix build and function issues of fastboot for Android

to fix build issues, add two header files, "fastboot_lock_unlock.h" is
copied from imx_v2018.03 branch, "fb_fsl_common.h" contains some
varialbes and a function used in more than one files.

the places where "fastboot_lock_unlock.h" is included is modified to
adapt to this change.
"fsl_fastboot.h" is renamed to "fb_fsl.h", the places where
"fsl_fastboot.h" is included is modified to adapt to this change.

to fix function issues, command handle function in "fb_fsl_command.c" is
modified.

build based on imx8mm_ddr4_evk, the board can boot and basic fastboot
function can work.

Change-Id: I34961ef70351a1ee4c84b6721dba5ac7b261a0d3
Signed-off-by: faqiang.zhu <faqiang.zhu@nxp.com>