fix up access type of CHAN_ABORT register in RP2040.svd and RP2350.svd

Author: kilograham

src/rp2040/hardware_regs/RP2040.svd

@@ -32214,7 +32214,8 @@ SPDX-License-Identifier: BSD-3-Clause
 
                             After writing, this register must be polled until it returns all-zero. Until this point, it is unsafe to restart the channel.</description>
                         <bitRange>[15:0]</bitRange>
-                        <access>write-only</access>
+                        <access>read-write</access>
+                        <modifiedWriteValues>clear</modifiedWriteValues>
                     </field>
                 </fields>
             </register>

src/rp2350/hardware_regs/RP2350.svd

@@ -62229,7 +62229,8 @@ SPDX-License-Identifier: BSD-3-Clause
 
                             After writing, this register must be polled until it returns all-zero. Until this point, it is unsafe to restart the channel.</description>
                         <bitRange>[15:0]</bitRange>
-                        <access>write-only</access>
+                        <access>read-write</access>
+                        <modifiedWriteValues>oneToClear</modifiedWriteValues>
                     </field>
                 </fields>
             </register>