ARM: EXYNOS: Add apb_pclk clkdev entry for mdma1

Amba core assumes the pclk to be named as apb_pclk. During device probe,
it tries to get that clock and enable that. When PM_RUNTIME is enabled,
dma clock is not explicitly enabled in pl330_probe, which causes device
probe to fail. Adding a clkdev entry for apb_pclk for mdma1 fixes the
problem.

This patch fixes following runtime error.

dma-pl330 dma-pl330.2: PERIPH_ID 0x0, PCELL_ID 0x0 !
dma-pl330: probe of dma-pl330.2 failed with error -22
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-exynos/clock-exynos4.c

@@ -1338,6 +1338,7 @@ static struct clk_lookup exynos4_clk_lookup[] = {
 	CLKDEV_INIT("s3c-sdhci.3", "mmc_busclk.2", &exynos4_clk_sclk_mmc3.clk),
 	CLKDEV_INIT("dma-pl330.0", "apb_pclk", &exynos4_clk_pdma0),
 	CLKDEV_INIT("dma-pl330.1", "apb_pclk", &exynos4_clk_pdma1),
+	CLKDEV_INIT("dma-pl330.2", "apb_pclk", &exynos4_clk_mdma1),
 	CLKDEV_INIT("s3c64xx-spi.0", "spi_busclk0", &exynos4_clk_sclk_spi0.clk),
 	CLKDEV_INIT("s3c64xx-spi.1", "spi_busclk0", &exynos4_clk_sclk_spi1.clk),
 	CLKDEV_INIT("s3c64xx-spi.2", "spi_busclk0", &exynos4_clk_sclk_spi2.clk),