kernel/sim-armv7: Fix os_arch_frame_init symbol type
kernel/sim-armv7: Fix os_arch_frame_init symbol type

Without symbol type GNU ld does not properly detect call to ARM code
from Thumb code and does not generate proper instruction to switch
modes which results in a crash.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core