hw/timer/exynos4210_mct: Fix checkpatch style errors

Fix checkpatch errors:
1. ERROR: spaces required around that '+' (ctx:VxV)
2. ERROR: spaces required around that '&' (ctx:VxV)

No functional changes.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
