ARM: dts: Fix dcan driver probe failed on am437x platform

ARM: dts: Fix dcan driver probe failed on am437x platform

Got following d_can probe errors with kernel 5.8-rc1 on am437x

[   10.730822] CAN device driver interface
Starting Wait for Network to be Configured...
[  OK  ] Reached target Network.
[   10.787363] c_can_platform 481cc000.can: probe failed
[   10.792484] c_can_platform: probe of 481cc000.can failed with error -2
[   10.799457] c_can_platform 481d0000.can: probe failed
[   10.804617] c_can_platform: probe of 481d0000.can failed with error -2

actually, Tony has fixed this issue on am335x with the patch [3]

Since am437x has the same clock structure with am335x
[1][2], so reuse the code from Tony Lindgren's patch [3] to fix it.

[1]: https://www.ti.com/lit/pdf/spruh73 Chapter-23, Figure 23-1. DCAN
     Integration
[2]: https://www.ti.com/lit/pdf/spruhl7 Chapter-25, Figure 25-1. DCAN
     Integration
[3]: commit 516f1117d0fb ("ARM: dts: Configure osc clock for d_can on
     am335x")

Fixes: 1a5cd7c23cc5 ("bus: ti-sysc: Enable all clocks directly during init to read revision")
Signed-off-by: dillon min <dillon.minfei@gmail.com>
[tony@atomide.com: aligned commit message a bit for readability]
Signed-off-by: Tony Lindgren <tony@atomide.com>