ARM: exynos: Fix "allmodconfig" build errors in mcpm and hotplug

This fixes the following build errors:

/tmp/ccRbZlaA.s: Assembler messages:
/tmp/ccRbZlaA.s:69: Error: selected processor does not support ARM mode `isb '
/tmp/ccRbZlaA.s:75: Error: selected processor does not support ARM mode `isb '
/tmp/ccRbZlaA.s:76: Error: selected processor does not support ARM mode `dsb '
make[1]: *** [arch/arm/mach-exynos/hotplug.o] Error 1

/tmp/ccJEg4jw.s: Assembler messages:
/tmp/ccJEg4jw.s:454: Error: selected processor does not support ARM mode `isb'
/tmp/ccJEg4jw.s:455: Error: selected processor does not support ARM mode `dsb'
/tmp/ccJEg4jw.s:465: Error: selected processor does not support ARM mode `isb'
/tmp/ccJEg4jw.s:474: Error: selected processor does not support ARM mode `isb'
/tmp/ccJEg4jw.s:475: Error: selected processor does not support ARM mode `dsb'
/tmp/ccJEg4jw.s:516: Error: selected processor does not support ARM mode `isb'
/tmp/ccJEg4jw.s:525: Error: selected processor does not support ARM mode `isb'
/tmp/ccJEg4jw.s:526: Error: selected processor does not support ARM mode `dsb'
make[1]: *** [arch/arm/mach-exynos/mcpm-exynos.o] Error 1

Reported-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Tested-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>