clk: at91: fix the build with binutils 2.27

clk: at91: fix the build with binutils 2.27

There is an issue when build with older versions of binutils 2.27.0,

arch/arm/mach-at91/pm_suspend.S: Assembler messages:
arch/arm/mach-at91/pm_suspend.S:1086: Error: garbage following instruction -- `ldr tmp1,=0x00020010UL'

Use UL() macro to fix the issue in assembly file.

Fixes: bb199ebb8a3e ("ARM: at91: pm: add plla disable/enable support for sam9x60")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20221012030635.13140-1-wangkefeng.wang@huawei.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>