Rename new R6 O32 MIPS architectures to remove the 32 suffix

The new arch names for the R6 O32 variants do not follow the same
convention as the pre-existing O32 architectures. Which is rather
confusing. In addition the confusion would be worsened by having
mips32r6 and mipsn32r6 for the O32 and N32 ABIs.

Signed-off-by: YunQiang Su <wzssyqa@gmail.com>
Signed-off-by: Guillem Jover <guillem@debian.org>

cputable

@@ -27,8 +27,8 @@ m32r		m32r		m32r			32	big
 m68k		m68k		m68k			32	big
 mips		mips		mips(eb)?		32	big
 mipsel		mipsel		mipsel			32	little
-mips32r6	mipsisa32r6	mipsisa32r6		32	big
-mips32r6el	mipsisa32r6el	mipsisa32r6el		32	little
+mipsr6		mipsisa32r6	mipsisa32r6		32	big
+mipsr6el	mipsisa32r6el	mipsisa32r6el		32	little
 mips64		mips64		mips64			64	big
 mips64el	mips64el	mips64el		64	little
 mips64r6	mipsisa64r6	mipsisa64r6		64	big