ARM: uniphier: enable Peripherl clock to use UART in SPL

This is needed to use UART on SPL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

arch/arm/mach-uniphier/early-clk/early-clk-ld20.c

@@ -21,6 +21,10 @@ int uniphier_ld20_early_clk_init(const struct uniphier_board_data *bd)
 	writel(tmp, SC_RSTCTRL7);
 
 	/* provide clocks */
+	tmp = readl(SC_CLKCTRL4);
+	tmp |= SC_CLKCTRL4_PERI;
+	writel(tmp, SC_CLKCTRL4);
+
 	tmp = readl(SC_CLKCTRL7);
 	tmp |= SC_CLKCTRL7_UMCSB | SC_CLKCTRL7_UMC32 | SC_CLKCTRL7_UMC31 |
 							SC_CLKCTRL7_UMC30;