ARM: SAMSUNG: Add missing variable declaration in s3c64xx_spi1_set_platdata()

Fixes regression introduced in commit 4d0efdd5

 ("ARM: SAMSUNG:
Modify s3c64xx_spi{0|1|2}_set_platdata function")

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>