clk: tm2: add CLK_IGNORE_UNUSED flag for pcie gates [1/1]

clk: tm2: add CLK_IGNORE_UNUSED flag for pcie gates [1/1]

PD#SWPL-7855

Problem:
pcie A does not work when enable alone

---hcsl_r_exen[bit29]---pcie A gate [bit3]
                     |
                     ---pcie B gate [bit28]

bit29/bit28: HHI_PCIE0_PLL_CNTL1
bit3: HHI_PCIE0_PLL_CNTL5

clk core will disable unused clock, So
CLK_IGNORE_UNUSED flag is necessary for
the three gates to avoid closing.

Solution:
add CLK_IGNORE_UNUSED flag for pcie gates

Verify:
test passed on tm2 ab31

Change-Id: I1121c75ab8fb847ec2ba1f7a0975619b36b0938e
Signed-off-by: Jian Hu <jian.hu@amlogic.com>