Fix typos in arm-none-eabi.md

These arrived in rust-lang#125690, I think by mistake.

src/doc/rustc/src/platform-support/arm-none-eabi.md

@@ -42,16 +42,15 @@ their own document.
 There are two 32-bit instruction set architectures (ISAs) defined by Arm:
 
 - The [*A32 ISA*][a32-isa], with fixed-width 32-bit instructions. Previously
-  known as the *Arm* ISA, this originated with the original Arm1 of 1985 and has
+  known as the *Arm* ISA, this originated with the original ARM1 of 1985 and has
   been updated by various revisions to the architecture specifications ever
   since.
 - The [*T32 ISA*][t32-isa], with a mix of 16-bit and 32-bit width instructions.
   Note that this term includes both the original 16-bit width *Thumb* ISA
   introduced with the Armv4T architecture in 1994, and the later 16/32-bit sized
-  *Thumb-2* ISA introduced with the Armv6T2 architecture in 2003.
-
-Again, these ISAs have been revised by subsequent revisions to the relevant Arm
-architecture specifications.
+  *Thumb-2* ISA introduced with the Armv6T2 architecture in 2003. Again, these
+  ISAs have been revised by subsequent revisions to the relevant Arm
+  architecture specifications.
 
 There is also a 64-bit ISA with fixed-width 32-bit instructions called the *A64
 ISA*, but targets which implement that instruction set generally start with