ARM: STi: Update machine _namestr to be more generic.

ARM: STi: Update machine _namestr to be more generic.

This string is used by dump_stack and as we now support
more SoC's than just STiH415/6 it is misleading to have
the current string in the stack trace.

This patch updates it to be more generic for the STi
family of SoCs.

So instead of looking like this

[  271.672555] Hardware name: STiH415/416 SoC with Flattened Device Tree
[  271.678998] [<c0310490>] (unwind_backtrace) from [<c030bb54>] (show_stack+0x10/0x14)
[  271.686746] [<c030bb54>] (show_stack) from [<c058bc4c>] (dump_stack+0x98/0xac)
[snip]

it now looks like this:

[    2.669879] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc3-00026-g38a1ce6-dirty #76
[    2.677973] Hardware name: STi SoC with Flattened Device Tree
[    2.683723] [<c0310490>] (unwind_backtrace) from [<c030bb54>] (show_stack+0x10/0x14)
[    2.691472] [<c030bb54>] (show_stack) from [<c058bc0c>] (dump_stack+0x98/0xac)
[snip]

Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>