clk: mxl: Fix a clk entry by adding relevant flags

One of the clock entry "dcl" clk has some HW limitations. One is that
its rate can only by changed by changing its parent clk's rate & two is
that HW does not support enable/disable for this clk.

Handle above two limitations by adding relevant flags. Add standard flag
CLK_SET_RATE_PARENT to handle rate change and add driver internal flag
DIV_CLK_NO_MASK to handle enable/disable.

Fixes: d058fd9e ("clk: intel: Add CGU clock driver for a new SoC")
Reviewed-by: Yi xin Zhu <yzhu@maxlinear.com>
Signed-off-by: Rahul Tanwar <rtanwar@maxlinear.com>
Link: https://lore.kernel.org/r/a4770e7225f8a0c03c8ab2ba80434a4e8e9afb17.1665642720.git.rtanwar@maxlinear.comSigned-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/x86/clk-cgu.c

@@ -164,6 +164,7 @@ static int lgm_clk_divider_enable_disable(struct clk_hw *hw, int enable)
 {
 	struct lgm_clk_divider *div = to_lgm_clk_divider(hw);
 
+	if (div->flags != DIV_CLK_NO_MASK)
 		lgm_set_clk_val(div->membase, div->reg, div->shift_gate,
 				div->width_gate, enable);
 	return 0;

drivers/clk/x86/clk-cgu.h

@@ -198,6 +198,7 @@ struct lgm_clk_branch {
 #define CLOCK_FLAG_VAL_INIT	BIT(16)
 #define MUX_CLK_SW		BIT(17)
 #define GATE_CLK_HW		BIT(18)
+#define DIV_CLK_NO_MASK		BIT(19)
 
 #define LGM_MUX(_id, _name, _pdata, _f, _reg,		\
 		_shift, _width, _cf, _v)		\

drivers/clk/x86/clk-lgm.c

@@ -255,8 +255,8 @@ static const struct lgm_clk_branch lgm_branch_clks[] = {
 	LGM_FIXED(LGM_CLK_SLIC, "slic", NULL, 0, CGU_IF_CLK1,
 		  8, 2, CLOCK_FLAG_VAL_INIT, 8192000, 2),
 	LGM_FIXED(LGM_CLK_DOCSIS, "v_docsis", NULL, 0, 0, 0, 0, 0, 16000000, 0),
-	LGM_DIV(LGM_CLK_DCL, "dcl", "v_ifclk", 0, CGU_PCMCR,
-		25, 3, 0, 0, 0, 0, dcl_div),
+	LGM_DIV(LGM_CLK_DCL, "dcl", "v_ifclk", CLK_SET_RATE_PARENT, CGU_PCMCR,
+		25, 3, 0, 0, DIV_CLK_NO_MASK, 0, dcl_div),
 	LGM_MUX(LGM_CLK_PCM, "pcm", pcm_p, 0, CGU_C55_PCMCR,
 		0, 1, CLK_MUX_ROUND_CLOSEST, 0),
 	LGM_FIXED_FACTOR(LGM_CLK_DDR_PHY, "ddr_phy", "ddr",