ARM: 7780/1: add missing linker section markup to head-common.S

Macro __INIT is used to place various code in head-common.S into the init
section. This should be matched by a closing __FINIT. Also, add an
explicit ".text" to ensure subsequent code is placed into the correct
section; __FINIT is simply a closing marker to match __INIT and doesn't
guarantee to revert to .text.

This historically caused no problem, because macro __CPUINIT was used at
the exact location where __FINIT was missing, which then placed following
code into the cpuinit section. However, with commit 22f0a2736 "init.h:
remove __cpuinit sections from the kernel" applied, __CPUINIT becomes a
no-op, thus leaving all this code in the init section, rather than the
regular text section. This caused issues such as secondary CPU boot
failures or crashes.

Change-Id: I2c346b58c4c4d50a162b19e9967d44ec5e97c7d4
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>