MIPS: BMIPS: Fix section mismatch warning

Remove the __init annotation from bmips_cpu_setup() to avoid the
following warning.

WARNING: vmlinux.o(.text+0x35c950): Section mismatch in reference from the function brcmstb_pm_s3() to the function .init.text:bmips_cpu_setup()
The function brcmstb_pm_s3() references
the function __init bmips_cpu_setup().
This is often because brcmstb_pm_s3 lacks a __init
annotation or the annotation of bmips_cpu_setup is wrong.

Signed-off-by: Jaedon Shin <jaedon.shin@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Reviewed-by: James Hogan <jhogan@kernel.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/18589/


Signed-off-by: James Hogan <jhogan@kernel.org>