nvptx.opt: Add sm_89 and sm_90a to -march-map=

The -march-map= options maps the compute capability to the closest
lower compute capability that has been implemented; for sm_89 and
sm_90a, that were previously missing, that's currently -march=sm_80
alias -misa=sm_80.

gcc/ChangeLog:

	* config/nvptx/nvptx.opt (march-map=): Add sm_89 and sm_90a.

Signed-off-by: Tobias Burnus <tburnus@baylibre.com>

diff --git a/gcc/config/nvptx/nvptx.opt b/gcc/config/nvptx/nvptx.opt
index 09d75fca037..deb006663d7 100644
--- a/gcc/config/nvptx/nvptx.opt
+++ b/gcc/config/nvptx/nvptx.opt
@@ -108,9 +108,15 @@ Target RejectNegative Alias(misa=,sm_80)
 march-map=sm_87
 Target RejectNegative Alias(misa=,sm_80)
 
+march-map=sm_89
+Target RejectNegative Alias(misa=,sm_80)
+
 march-map=sm_90
 Target RejectNegative Alias(misa=,sm_80)
 
+march-map=sm_90a
+Target RejectNegative Alias(misa=,sm_80)
+
 Enum
 Name(ptx_version) Type(int)
 Known PTX ISA versions (for use with the -mptx= option):