pinctrl: samsung: Define suspend and resume callbacks for all banks and SoCs

Suspend and resume callbacks in Exynos/S5Pv210 pin controller drivers,
save and restore state of registers.  This operations should be done for
all banks which have external interrupts (as denoted by using
EXYNOS_PIN_BANK_EINTG/EINTW macros).

Add all banks of Exynos5260 and Exynos5420.  This is necessary step for
supporting suspend to RAM on these SoCs.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Sylwester Nawrocki <snawrocki@kernel.org>
Acked-by: Tomasz Figa <tomasz.figa@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>