[arch][arm] Remove hardcoded phys-offset from startup code
[arch][arm] Remove hardcoded phys-offset from startup code

The fixed phys offset does not work if the load address is not known at
compile time.

Change-Id: I50e669829a8d29d8bdcf6296b3537595f060d808

GCrean/lk,GCrean/lk,sndnvaps/lk,GCrean/lk,hollanderic/lkstuff,sndnvaps/lk,srodrig1/lk,ErikCorryGoogle/lk,travisg/lk,ErikCorryGoogle/lk,travisg/lk,sndnvaps/lk,skabet/lk,minglun-tsai/lk,littlekernel/lk,srodrig1/lk,nvll/lk,grub4android/lk,grub4android/lk,hollanderic/lkstuff,skabet/lk,srodrig1/lk,nvll/lk,nvll/lk,littlekernel/lk,sndnvaps/lk,travisg/lk,minglun-tsai/lk,hollanderic/lkstuff,littlekernel/lk,ErikCorryGoogle/lk,littlekernel/lk,nvll/lk,skabet/lk,sndnvaps/lk,grub4android/lk,travisg/lk,minglun-tsai/lk,srodrig1/lk,GCrean/lk,ErikCorryGoogle/lk,minglun-tsai/lk,skabet/lk,grub4android/lk,grub4android/lk,GCrean/lk,srodrig1/lk,nvll/lk,hollanderic/lkstuff,skabet/lk