sunxi: do a CCM quirk on V3s for USB to work properly

USB OTG on V3s SoC seems to need the USB OTG clock gate to be passed and
the reset to be deasserted before boot, otherwise it won't work in
Linux.

Add this quirk.

Also add a generic quirk framework in sunxi's clock initialization code.

Signed-off-by: Icenowy Zheng <icenowy@aosc.xyz>

arch/arm/include/asm/arch-sunxi/clock_sun6i.h

@@ -376,6 +376,7 @@ struct sunxi_ccm_reg {
 #define CCM_PLL11_PATTERN		0xf5860000
 
 /* ahb_reset0 offsets */
+#define AHB_RESET_OFFSET_OTG		24
 #define AHB_RESET_OFFSET_GMAC		17
 #define AHB_RESET_OFFSET_MCTL		14
 #define AHB_RESET_OFFSET_MMC3		11

arch/arm/mach-sunxi/clock.c

@@ -20,6 +20,10 @@ __weak void clock_init_sec(void)
 {
 }
 
+__weak void clock_init_quirk(void)
+{
+}
+
 __weak void gtbus_init(void)
 {
 }
@@ -32,6 +36,7 @@ int clock_init(void)
 #endif
 	clock_init_uart();
 	clock_init_sec();
+	clock_init_quirk();
 
 	return 0;
 }

arch/arm/mach-sunxi/clock_sun6i.c

@@ -58,6 +58,17 @@ void clock_init_sec(void)
 #endif
 }
 
+void clock_init_quirk(void)
+{
+	/* without this quirk, the USB PHY cannot be used in Linux */
+#ifdef CONFIG_MACH_SUN8I_V3S
+       struct sunxi_ccm_reg * const ccm =
+               (struct sunxi_ccm_reg *)SUNXI_CCM_BASE;
+       setbits_le32(&ccm->ahb_gate0, 1 << AHB_GATE_OFFSET_USB0);
+       setbits_le32(&ccm->ahb_reset0_cfg, 1 << AHB_RESET_OFFSET_OTG);
+#endif
+}
+
 void clock_init_uart(void)
 {
 #if CONFIG_CONS_INDEX < 5